Monday, May 17, 2010

Resurrection Plant

Common names:
Resurrection Plant, Rose of Jericho, Dinosaur Plant, Siempre Viva (meaning Everlasting)

Scientific name:
Selaginella lepidophylla

Explanation of scientific name:
Selaginella - from the Latin "selago" (A type of juniper we now call savin juniper. Selaginellas have juniper-like foliage.), and the Latin "ella" meaning small.
lepidophylla - from the Latin meaning scaly-leaved.




The Resurrection Plant is one of over 700 species in the Selaginella genus of plants. All of them are primitive plants, fitting somewhere between mosses and ferns in the hierarchy of plant evolution. They belong to a group of plants known as the lycopods, whose members go by the common names of ground pines and club mosses. All are relatively small (up to one foot tall) and are found around the world, usually in moist locations with mosses and ferns. They reproduce by single-celled spores, and lack flowers, fruits and seeds. Even their "leaves" are not really leaves, but instead leaf-like extensions of the stem. What lycopods consist of then are roots, stems with scales, and club-like strobili that produce spores.
What distinguishes the Resurrection Plant from most other lycopods is where it lives and how it copes with its environment. Found from Texas and Arizona south to El Salvador, the Resurrection plant is a desert inhabitant. Growing from rock outcroppings or in dry soil, its close neighbors would be mostly cacti and other arid-loving species. Under these conditions, most other lycopods would perish, but the Resurrection Plant thrives.
When the soil is moist after infrequent rains, a Resurrection Plant absorbs water and grows rapidly, producing a flat rosette of scaly stems up to one foot across. As the soil dries, it cannot store water like its succulent neighbors, so it folds up its stems into a tight ball as it desiccates and goes into a state of dormancy. The folded plant has a limited surface area, and what little internal moisture is present is conserved. All metabolic functions are reduced to a bare minimum and it appears to be dead. The plant can remain in this dormant condition for years. When the rains return, the plant's cells rehydrate. The stems unfold, metabolism increases, and growth resumes. Even dead Resurrection plants will unfold if given water, since rehydrated cells expand even if there is no living protoplasm in them.
The Resurrection Plant's ability to seemingly return from the dead certainly justifies its common name, and has led to its use as a novelty plant. Collected from the wild in the South West US and Mexico, it is sold to tourists and exported worldwide.
As a lycopod, the Resurrection Plant can trace its ancestors far back into history. They appeared at least 400 million years ago as small plants similar in appearance to those that are alive today. Their period of prominence however, came later. Between 345 and 280 million years ago they dominated the plant world as giant trees over 100 feet tall with trunks 6 feet in diameter at the base. These swamp inhabiting trees became important contributors to the coal deposits we exploit today. Cooler climates and other as yet unidentified factors caused these giant lycopods to become extinct. But their smaller relatives, like the Resurrection Plant, persisted in a changing world.
Today the lycopods make up an inconspicuous remnant of what were once the largest plants on earth. The ability to adapt to one's surroundings has always been the key to survival. In that respect the seemingly insignificant Resurrection Plant is an eminent example of perseverance.

Resurrection Plant, something between moss and fern
Guest Author - Alegra M. Bartzat

Selaginella lepidophylla is the scientific name for the plant more commonly known as Resurrection Plant, Rose of Jericho, or Siempre Viva (Everlasting).

Selaginella comes from "selago," the Latin name for a type of Juniper. It means "Little Juniper." Lepidophylla is Latin for scaly-leaved. So the scientific names means "scaly leaved little juniper." However, the Resurrection plant is not related to the Juniper; it only has a similar appearance.

The Resurrection Plant lives in a desert environment, from the Southwest United States Sonoran and Chihuahan Deserts into Mexico and Central America, all the way down to El Salvador. While this tropical and sub-tropical climate range shares many common species, the Resurrection Plant is unique among them because it is one of the only lycopods to live in the desert.

Lycopods are ancient plants, which have not evolved in millennia. Evidence of their existence, almost unchanged, can be dated back 400 million years. Lycopods have only roots, stems with scales, and strobili, which are structures that produce spores. In this way, they are similar to the other spore-producing plants moss and ferns. They do not have true leaves.

Resurrection Plants get their name form their evolved trait that allows them to cope with long periods of dry weather. When it rains, they grow large and lush very quickly, but when the air and earth become dry, the Resurrection Plant curls up into a tight ball, preserving a small amount of water in its center. In this form it can survive long seasons without water, and when the rains return they unfurl, seemingly coming back from the dead!

Because of this quirky characteristic, the Resurrection Plant is actually sold as novelty plant to tourists in the Southwestern USA and parts of Mexico and Central America as a gimmick. This strange trait does allow this plant that normally would thrive with water-loving plants to survive in the desert with cactus and other dry-loving plants.


One Exotic Houseplant that is Hard to Kill

One of the most amazing exotic houseplants available today is native from Texas and Arizona, south to El Salvador, Mexico. If a houseplant that can be considered an easy keeper, to the point of being capable of thriving

The Resurrection Plant, also know as Selaginella lepidophylla, is aptly named due to its ability to "return from the dead". This interesting and intriguing plant, which thrives in desert conditions, has the ability to lie dormant and shrivel up into a ball when the moisture content of its soil dries up. It will appear to be dead, but actually, it is not. With just a little moisture added, the Resurrection Plant will begin to absorb the moisture; it will unfold from its ball and begin to grow rapidly. During this time, this exotic houseplant will produce a flat rosette of scaly stems and leaf structures. These leaf structures are actually extensions of its stems. When the soil is permitted to dry out, the Resurrection Plant will once again fold up into a ball and go dormant. The plant can remain dormant for years. This behavior is why the Resurrection Plant is on the list of exotic houseplants that are finding themselves in people's homes.

The Resurrection Plant, which is also called the Rose of Jericho is actually a plant that is classified somewhere between a moss and a fern. This small plant is very easy to care for; place it in a shallow dish and watered it periodically. It can also be planted in a shallow pot with potting soil. It is important to remember that this interesting exotic houseplant grows when its soil is moist. This moisture causes the plant cells to rehydrate, the stems to unfold and metabolism to increase allowing growth to occur. So, for growth to occur, water is important, more important than any other element.

The unique nature of the Resurrection Plant does not end with its ability to become dormant in drought conditions. Its uniqueness carries over into the way to reproduce as well. Propagation for this exotic houseplant occurs with single-celled spores produced by the plants club-like strobill. Unlike most plants, this exotic houseplant has no flowers, no seeds and no fruits. With the way this plant reproduces it does not generally occur when kept indoors. It may actually be difficult to propagate at all.

If you are looking for a new, interesting houseplant that does well in any location, and does not require any extra attention, then the Resurrection Plant maybe just what you need. This can be especially true if you tend to be neglectful when it comes to caring for your houseplants. This unusual plant is also perfect for the younger plant owner. Kids will be amazed at the way it will spring back to life after looking very dead. So go ahead, try it, you may just find you have a new favorite, exotic houseplant.

How would you like a houseplant that you only had to water when you felt like it? A houseplant that can take weeks, months, even years without water and yet springs back to life and looks great just three hours after the water returns? Well, it does exist; it’s called the dinosaur plant.

It’s a fairly old plant that did, in fact, exist while dinosaurs roamed the earth. Unlike the vast majority of our garden plants, resurrection plants are seedless vascular plants. In other words, like most garden plants they contain structures in the stems that allow water and nutrients to flow through the plant, but unlike most plants, they produce spores rather than seeds.
Resurrection plants are poikilohydrous, which essentially means that their water content varies with the relative humidity of the surrounding environment. It’s a remarkable adaptation to desert environments. No wonder there has been some research to see if the drought resistance genes of this plant could be utilized for breeding drought resistant agricultural crops.


How to Grow a Resurrection Plant

Overview
The name resurrection plant can apply to a whole group of plants that appear to die when unwatered and spring back to life when watered. The most common plant sold under the name resurrection plant is selaginella lepidophylla, a primitive desert plant that is also called rose of Jericho or siempre viva (everlasting). A resurrection plant that has balled up and appears dried out is simply dormant from lack of water. If you want to properly grow and care for this plant, you shouldn't let this condition last for extreme periods, as contrary to its name, it can die.

Step 1
Set up an appropriate habitat for your resurrection plant. These do not require soil like most plants; you can think of them more like a moss or lichen. Set out a clay or ceramic dish of your choice that has a lip to keep water from spilling over.

Step 2
Put a thin layer of fine gravel in the dish. Resurrection plant doesn't have roots; it simply grows in a self-contained ball. Setting it on the gravel will keep it from soaking in the water and rotting. Pour a shallow layer of water into the gravel and place the plant on top of the gravel.

Step 3
Place the plant in the sun. Resurrection plant is a desert plant, and is designed for long hours of sunlight and warmth. It should be in a location where it gets direct sun for about 12 hours a day. It doesn't tolerate temperatures below about 40 degrees Fahrenheit

Step 4
Water rarely. Let the resurrection plant go without water until it begins to curl up. The plant uses water very efficiently, and this is the best way to be sure you are not over-watering it.

Step 5
Divide the plant by cutting. It sprouts quickly from new cuttings at any time of year. Just place the cuttings in moist compost or loose soil and water.


THE ELEMENTS AND BENEFITS

TREHALOSE

Trehalose 6-Phosphate Synthase From Selaginella Lepidophylla:
Purification And Properties

Abstract

A protein of 440 kDa with trehalose 6-phosphate synthase activity was purified with only one purification step by immobilized metal affinity chromatography, from fully hydrated Selaginella lepidophylla plants. The enzyme was purified 50-fold with a yield of 89% and a specific activity of 7.05 U/mg protein. This complex showed two additional aggregation states of 660 and 230 kDa. The three complexes contained 50, 67, and 115 kDa polypeptides with pI of 4.83, 4.69, and 4.55. The reaction was highly specific for glucose 6-phosphate and UDP-glucose. The optimum pH was 7.0 and the enzyme was stable from pH 5.0 to 10. The enzyme was activated by low concentrations of Ca2+, Mg2+, K+, and Na+ and by fructose 6-phosphate, fructose, and glucose. Proline had an inhibitory effect, while sucrose and trehalose up to 0.4 M did not have any effect on the activity. Neither the substrates nor final product had an inhibitory effect.
Plants, such as Arabidopsis thaliana and Selaginella lepidophylla, contain genes homologous with the trehalose-6-phosphate synthase (TPS) genes of bacteria and fungi. Most plants do not accumulate trehalose with the desert resurrection plant S. lepidophylla, being a notable exception. Overexpression of the plant genes in a Saccharomyces cerevisiae tps1 mutant results in very low TPS-catalytic activity and trehalose accumulation. We show that truncation of the plant-specific N-terminal extension in the A. thaliana AtTPS1 and S. lepidophylla SlTPS1 homologues results in 10-40-fold higher TPS activity and 20-40-fold higher trehalose accumulation on expression in yeast. These results show that the plant TPS enzymes possess a high-potential catalytic activity. The growth defect of the tps1 strain on glucose was restored, however, the proper homoeostasis of glycolytic flux was not restored, indicating that the plant enzymes were unable to substitute for the yeast enzyme in the regulation of hexokinase activity. Further analysis of the N-terminus led to the identification of two conserved residues, which after mutagenesis result in strongly enhanced trehalose accumulation upon expression in yeast. The plant-specific N-terminal region may act as an inhibitory domain allowing modulation of TPS activity.
Trehalose, also known as mycose, is a natural alpha-linked disaccharide formed by an α, α-1, 1-glucoside bond between two α-glucose units. In 1832 Wiggers discovered trehalose in rye and in 1859 Berthelot isolated it from trehala manna (manna) made by weevils, and named it trehalose. It can be synthesised by fungi, plants, and invertebrate animals. It is implicated in anhydrobiosis — the ability of plants and animals to withstand prolonged periods of desiccation. It has high water retention capabilities and is used in food and cosmetics. The sugar is thought to form a gel phase as cells dehydrate, which prevents disruption of internal cell organelles by effectively splinting them in position. Rehydration then allows normal cellular activity to be resumed without the major, lethal damage that would normally follow a dehydration/reyhdration cycle. Trehalose has the added advantage of being an antioxidant. Extracting trehalose used to be a difficult and costly process, but, recently, the Hayashibara company (Okayama, Japan) confirmed an inexpensive extraction technology from starch for mass production. Trehalose is now being used for a broad spectrum of applications, as mentioned above.

Structure
Trehalose is a disaccharide formed by a 1, 1-glucoside bond between two α-glucose units. Because trehalose is formed by the bonding of two reducing groups, it has no reducibility.

Chemical properties
Trehalose was first isolated from ergot of rye. Emil Fischer first described the trehalose-hydrolyzing enzyme in yeast. Trehalose is a non-reducing sugar formed from two glucose units joined by a 1-1 alpha bond giving it the name of α-D-glucopyranosyl-(1→1)-α-D-glucopyranoside. The bonding makes trehalose very resistant to acid hydrolysis, and therefore stable in solution at high temperatures even under acidic conditions. The bonding also keeps non-reducing sugars in closed-ring form, such that the aldehyde or ketone end-groups do not bind to the lysine or arginine residues of proteins (a process called glycation). Trehalose is broken down by the enzyme trehalase into glucose. Trehalose has about 45% the sweetness of sucrose. Trehalose is less soluble than sucrose, except at high temperatures (>80 °C). Trehalose forms a rhomboid crystal as the dihydrate, and has 90% of the calorific content of sucrose in that form. Anhydrous forms of trehalose readily regain moisture to form the dihydrate. Anhydrous forms of trehalose can show interesting physical properties when heat-treated.

Biological Properties
Trehalose can be found in nature, animals, plants, and microorganisms. In animals, trehalose is prevalent in shrimp, and also in insects, including grasshoppers, locusts, butterflies, and bees, in which blood-sugar is trehalose. The trehalose is then broken down into glucose by the catabolic enzyme trehalase for use. Trehalose is also present in the nutrition exchange liquid of hornets and their larvae.
In plants, the presence of trehalose is seen in sunflower seeds, selaginella mosses, and sea algae. Within the fungus family, it is prevalent in some mushrooms such as shitake, maitake (grifola fondosa), nameko (pholiota nameko), and Judas's ear (A. auricularia-judae) contain 1% to 17% percent of trehalose in dry weight form, and is also referred to as mushroom sugar. Trehalose can also be found in such microorganisms as baker's yeast and wine yeast.
When tardigrades (water bears) dry out, the glucose in their bodies changes to trehalose when they enter a state called cryptobiosis - a state wherein they appear dead. However, when they receive water, they revive and return to their metabolic state. It is also thought that the reason the larva of sleeping chironomid (polypedihum vanderplanki) and artemia (sea monkeys, brine shrimp) are able to withstand dehydration is because they store trehalose within their cells.
Even within the plant kingdom, selaginella mosses that grow in desert and mountainous areas, although they may be cracked and dried out, will turn green again and revive after a rain, because of the function of trehalose; it is called the resurrection plant. It is also said that the reason dried shitake mushrooms spring back into shape so well in water is because they contain trehalose.
The theories as to how trehalose works within the organism in the state of cryptobiosis are that of either the vitrification theory, a state that maintains limited molecular activity, or the water displacement theory, whereby water is replaced by trehalose[2], or a combination of the two theories are at work.  Trehalose is metabolized by a number of bacteria, including Streptococcus mutans, the common oral bacteria responsible for dental plaque.
The enzyme trehalase, a glycoside hydrolase, present but not abundant in most people, breaks trehalose into two glucose molecules, which can then be readily absorbed in the gut.
Trehalose is the major carbohydrate energy storage molecule used by insects for flight. One possible reason for this is that the double glycosidic linkage of trehalose, when acted upon by an insect trehalase, releases two molecules of glucose, which is required for the rapid energy requirements of flight. This is double the efficiency of glucose release from the storage polymer starch, for which cleavage of one glycosidic linkage releases only one glucose molecule.

Natural Sources
1)Trehala manna
2)Locust
3)Resurrection plant
4)Fungi

Production
Trehalose is being manufactured through an extraction process from cultured yeast, but, since it costs several tens of thousands of yen for 1 kg, it is being used only in a portion of cosmetics and chemicals.
In 1994, Hayashibara, a saccharified starch maker in Okayama prefecture, succeeded in what was thought to be impossible, discovering a method of inexpensively mass-producing trehalose from starch. The following year, Hayashibara started marketing trehalose by activating two enzymes, the glucosyltrehalose-producing enzyme that changes the reducing terminal of starch into a trehalose structure, and the trehalose free enzyme that detaches this trehalose structure. As a result, a high-purity trehalose from starch can be mass-produced for a very low price.

Use
Trehalose has been accepted as a novel food ingredient under the GRAS terms in the U.S. and the EU. Trehalose has also found commercial application as a food ingredient. The uses for trehalose span a broad spectrum that cannot be found in other sugars, the primary one being its use in the processing of foods. Trehalose is used in a variety of processed foods such as dinners, western and Japanese confectionery, bread, vegetables side dishes, animal-derived deli foods, pouch-packed foods, frozen foods, and beverages, as well as foods for lunches, eating out, or prepared at home. This use in such a wide range of products is due to the multi-faceted effects of trehalose's properties, such as its inherently mild sweet flavor, its preservative properties, which maintain the quality of the three main nutrients (carbohydrates, proteins, fats), its powerful water-retention properties that preserve the texture of foods by protecting them from drying out or freezing, its properties to suppress smells and tastes such as bitterness, stringency, harsh flavors, and the stench of raw foods, meats, and packaged foods, which when combined can potentially bring about promising results. However, less-soluble and less-sweet than sucrose, trehalose is seldom used as a direct replacement for conventional sweeteners, such as sucrose, regarded as the "gold standard." Technology for the production of trehalose was developed in Japan, where enzyme-based processes converts wheat and corn syrups to trehalose. It is also used as a protein-stabilizing agent in research [3]. It is particularly effective when combined with phosphate ions[4]. Trehalose has also been used in at least one biopharmaceutical formulation, the monoclonal antibody trastuzumab, marketed as Herceptin.
Cosmetics: Capitalizing on trehalose's moisture-retaining capacity, it is used as a moisturizer in many basic toiletries such as bath oils and hair growth tonics.
Pharmaceuticals: Using trehalose's properties to preserve tissue and protein to full advantage, it is used in organ protection solutions for organ transplants.
Other: Other fields of use for trehalose span a broad spectrum including fabrics that have deodorization qualities and are compatible to Japan's official 'Cool Biz' attire, plant activation, antibacterial sheets, and nutrients for larvae.

Environmental Risk Management Authority (ERMA)
Ngā Kaiwhakatūpato Whakararu Taiao
Search the ERMA Registers
Application NOC06008
Selaginella lepidophylla (Hooker & Greville) (NOC06008)

Trade or Other Names
Selaginella lepidophylla (plant, containment, Resurrection plant, Rose of Jericho)

Applicant
Central Tree Crops Research Trust

Purpose
Selaginella lepidophylla is a desert plant that produces a non toxic sugar called trehalose, that has in overseas research been shown to have potential for the treatment of Huntingtons Disease

Application Status
Decision Notified


What is Huntington disease?
Huntington disease is a progressive brain disorder that causes uncontrolled movements, mental and emotional problems, and loss of thinking ability (cognition).
Adult-onset Huntington disease, the most common form of this disorder, usually appears in a person's thirties or forties. Early signs and symptoms can include irritability, depression, small involuntary movements, poor coordination, and trouble learning new information or making decisions. As the disease progresses, involuntary jerking movements (chorea) become more pronounced. Affected individuals may have trouble walking, speaking, and swallowing. People with this disorder typically also experience changes in personality and a decline in thinking and reasoning abilities. Individuals with the adult-onset form of Huntington disease generally survive about 15 to 25 years after signs and symptoms begin.
A less common, early-onset form of Huntington disease begins in childhood or adolescence. Although both forms of the disorder involve movement problems and mental and emotional changes, some of the features of the early-onset form differ from those of the adult-onset form. In children, signs and symptoms can include slowness, clumsiness, frequent falling, rigidity, slurred speech, and drooling. School performance often declines as thinking and reasoning abilities become impaired. Seizures occur in 30 percent to 50 percent of individuals with this condition. The course of early-onset Huntington disease may be shorter than adult-onset Huntington disease; affected individuals generally survive 10 to 15 years after signs and symptoms appear.

How common is Huntington disease?

Huntington disease affects an estimated 3 to 7 per 100,000 people of European ancestry. The disorder appears to be less common in some other populations, including people of Japanese, Chinese, and African descent.

What genes are related to Huntington disease?

Mutations in the HD gene cause Huntington disease.
The HD gene provides instructions for making a protein called huntingtin. Although the function of this protein is unknown, it likely plays an important role in nerve cells. Huntington disease is caused by a mutation in which a DNA segment, known as a CAG repeat, is abnormally expanded within the HD gene. Normally, this segment is repeated 10 to 35 times within the gene. In people with Huntington disease, however, the CAG segment is repeated 36 to more than 120 times. The abnormally expanded CAG segment leads to the production of a huntingtin protein that contains a long stretch of the amino acid glutamine. (Amino acids are the building blocks of proteins.) The elongated protein disrupts the normal function of nerve cells in certain parts of the brain, and ultimately leads to the death of those cells. The dysfunction and loss of nerve cells cause the signs and symptoms of Huntington disease.
Read more about the HD gene.

How do people inherit Huntington disease?

This condition is inherited in an autosomal dominant pattern, which means one copy of the altered gene in each cell is sufficient to cause the disorder. An affected person usually inherits the altered gene from one affected parent. In rare cases, an individual with Huntington disease does not have a parent with the disorder.
As the altered HD gene is passed from one generation to the next, the size of the CAG repeat expansion often increases in size. Larger repeat expansions are usually associated with an earlier onset of signs and symptoms. This phenomenon is called anticipation.

What other names do people use for Huntington disease?
Huntington chorea
Huntington Chronic Progressive Hereditary Chorea
Huntington's Disease
Progressive Chorea, Chronic Hereditary (Huntington)

A Kidney-Fixing Selaginella
Yesterday, exploring a trail leading up the mountain through the scrub I saw a man across the valley wandering along the wooded slope obviously looking for something, occasionally stooping and placing what he'd found into a bag. I had to go see what he was collecting.
The only thing I could see unusual about the spot he'd been in was that here and there thin, stacked layers of slate rock outcropped, and on those rock faces grew a sizable colony of a special kind of Selaginella, probably SELAGINELLA LEPIDOPHYLLA.
Selaginella is a non-flowering, spore-producing, moss- like, branching plant that usually creeps over the ground or climbs things, or is sometimes erect. We have them in the North, especially in moist, protected spots such as at cliff bases, mossy areas next to streams, etc. Most Selaginella species are tropical, though. Selaginellas are their own kind of thing, having their own plant family.
What's special about the Selaginella I found yesterday was that it was so large, made a pretty rosette with its ferny leaves, but dried up into a ball when dry. Then when it's wet again it opens up like a huge, green snowflake. For this reason the plant is often known as the Resurrection Plant.
So, why had the fellow been collecting this plant? All over Mexico I see it sold in its dry, balled-up state in "Indian markets" as a medicinal plant, so when I got home I looked up Selaginella lepidophylla in my Las Plantas Medicinales de México and, sure enough, it's regarded as powerful medicine. It’s special medicinal properties are very good for use as a diuretic – a drug used to help increase the flow of urine. In Spanish Selaginella lepidophylla is known as Doradilla.

Diuresis


Diuresis regulation by ADH and aldosterone
Diuresis is the increased production of urine by the kidney.

Types and causes

The kidney normally produces up to 180 L of "pro-urine" (glomerular filtrate) per day, but reabsorbs most of this before it reaches the bladder.
Polyuria is increased diuresis. This may be due to large fluid intake, various illnesses (diabetes insipidus, osmotic diuresis due to diabetes mellitus or hypercalcemia) or various chemical substances (diuretics, caffeine, alcohol). It may also occur after supraventricular tachycardias, during an onset of atrial fibrillation, childbirth, and the removal of an obstruction within the urinary tract. Diuresis is restrained by antidiuretics such as ADH, angiotensin II and aldosterone.
Cold diuresis is the occurrence of increased urine production on exposure to cold.
Substances that increase diuresis are called diuretics. Coffee is an example of a proposed diuretic.
Substances that decrease diuresis allow more vasopressin or antidiuretic hormone (ADH) to be present in the kidney.
High-altitude diuresis occurs at altitudes above 10,000 ft and is a desirable indicator of adaptation to high altitudes. Mountaineers who are adapting well to high altitudes experience this type of diuresis. Urine output is thus an important indicator of adaptation to altitude (or lack thereof). Persons who produce less urine even in the presence of adequate fluid intake probably are not adapting well to altitude.

Diuretic

A diuretic is any drug that elevates the rate of bodily urine excretion (diuresis). There are several categories of diuretics. All diuretics increase the excretion of water from the body, although each class of diuretic does so in a distinct way.

High ceiling loop diuretics
High ceiling diuretics are diuretics that may cause a substantial diuresis - up to 20%[1] of the filtered load of NaCl and water. This is huge, compared to that normal renal sodium reabsorption leaves only ~0.4% of filtered sodium in the urine.
Loop diuretics have this ability, and is therefore often synonymous with high ceiling diuretics. Loop diuretics, such as furosemide, inhibit the body's ability to reabsorb sodium at the ascending loop in the kidney which leads to a retention of water in the urine as water normally follows sodium back into the extracellular fluid (ECF). Other examples of high ceiling loop diuretics include ethacrynic acid, torsemide and bumetanide.

Thiazides

Drugs such as hydrochlorothiazide act on the distal tubule and inhibit the Na-Cl symport leading to a retention of water in the urine as water normally follows penetrating solutes.

Potassium-sparing diuretics

These are diuretics which do not promote the secretion of potassium into the urine; thus, potassium is spared and not lost as much as in other diuretics. Such drugs include spironolactone which is a competitive antagonists of aldosterone. Aldosterone normally adds sodium channels in the principal cells of the collecting duct and late distal tubule of the nephron. Spironolactone prevents aldosterone from entering the principal cells, preventing sodium reabsorption. Other examples of potassium-sparing diuretics are amiloride and triamterene. These drugs bind to the sodium channels of the principal cells, inhibiting an aldosterone-induced increase in sodium reabsorption.

Osmotic diuretics

Compounds such as mannitol are filtered in the glomerulus, but cannot be reabsorbed. Their presence leads to an increase in the osmolarity of the filtrate. To maintain osmotic balance, water is retained in the urine.

High Blood Glucose

Glucose, like mannitol, is a sugar that can behave as an osmotic diuretic. Unlike mannitol, glucose is commonly found in the blood. However, in certain conditions such as diabetes mellitus, the concentration of glucose in the blood exceeds the maximum resorption capacity of the kidney. When this happens, glucose remains in the filtrate, leading to the osmotic retention of water in the urine. Use of some drugs, especially stimulants may also increase blood glucose and thus increase urination.

Uses

In medicine, diuretics are used to treat heart failure, liver cirrhosis, hypertension and certain kidney diseases. Some diuretics, such as acetazolamide, help to make the urine more alkaline and are helpful in increasing excretion of substances such as aspirin in cases of overdose or poisoning. Diuretics are often abused by sufferers of eating disorders, especially bulimics, in attempts at weight loss.
The antihypertensive actions of some diuretics (thiazides and loop diuretics in particular) are independent of their diuretic effect. That is, the reduction in blood pressure is not due to decreased blood volume resulting from increased urine production, but occurs through other mechanisms and at lower doses than that required to produce diuresis. Indapamide was specifically designed with this in mind, and has a larger therapeutic window for hypertension (without pronounced diuresis) than most other diuretics.



Chemically, diuretics are a diverse group of compounds that either stimulate or inhibit various hormones that naturally occur in the body to regulate urine production by the kidneys. Herbal medications are not inherently diuretics. They are more correctly called aquaretics.

Chemically, diuretics are a diverse group of compounds that either stimulate or inhibit various hormones that naturally occur in the body to regulate urine production by the kidneys. Herbal medications are not inherently diuretics. They are more correctly called aquaretics.

Adverse effects
The main adverse effects of diuretics are hypovolemia, hypokalemia, hyperkalemia, hyponatremia, metabolic alkalosis, metabolic acidosis and hyperuricemia [2]. Each are at risk of certain types of diuretics and present with different symptoms.


Diuretics

Definition

Diuretics are medicines that help reduce the amount of water in the body.

Purpose

Diuretics are used to treat the buildup of excess fluid in the body that occurs with some medical conditions such as congestive heart failure, liver disease, and kidney disease. Some diuretics are also prescribed to treat high blood pressure. These drugs act on the kidneys to increase urine output. This reduces the amount of fluid in the bloodstream, which in turn lowers blood pressure.

Description

There are several types of diuretics, also called water pills:
Loop diuretics, such as bumetanide (Bumex) and furosemide (Lasix), get their name from the loop-shaped part of the kidneys where they have their effect.
Thiazide diuretics include such commonly used diuretics as hydrochlorothiazide (HydroDIURIL, Esidrix), chlorothiazide (Diuril), and chlorthalidone (Hygroton).
Potassium-sparing diuretics prevent the loss of potassium, which is a problem with other types of diuretics. Examples of potassium-sparing diuretics are amiloride (Midamor) and triamterene (Dyrenium).
In addition, some medicines contain combinations of two diuretics. The brands Dyazide and Maxzide, for example, contain the thiazide diuretic hydrochlorothiazide with the potassium-sparing diuretic triamterene.
Some nonprescription (over-the-counter) medicines contain diuretics. However, the medicines described here cannot be bought without a physician's prescription. They are available in tablet, capsule, liquid and injectable forms.

Precautions

Seeing a physician regularly while taking a diuretic is important. The physician will check to make sure the medicine is working as it should and will watch for unwanted side effects.
Some people feel unusually tired when they first start taking diuretics. This effect usually becomes less noticeable over time, as the body adjusts to the medicine.
Because diuretics increase urine output, people who take this medicine may need to urinate more often, even during the night. Health care professionals can help patients schedule their doses to avoid interfering with their sleep or regular activities.
For patients taking the kinds of diuretics that rob potassium from the body, physicians may recommend adding potassium-rich foods or drinks, such as citrus fruits and juices, to the diet. Or they may suggest taking a potassium supplement or taking another medicine that keeps the body from losing too much potassium. If the physician recommends any of these measures, be sure to closely follow his or her directions. Do not make other diet changes without checking with the physician. People who are taking potassium-sparing diuretics should not add potassium to their diets, as too much potassium may be harmful.
People who take diuretics may lose too much water or potassium when they get sick, especially if they have severe vomiting and diarrhea. They should check with their physicians if they become ill.
These medicines make some people feel lightheaded, dizzy or faint when they get up after sitting or lying down. Older people are especially likely to have this problem. Drinking alcohol, exercising, standing for long periods or being in hot weather may make the problem worse. To lessen the problem, get up gradually and hold onto something for support if possible. Avoid drinking too much alcohol and be careful in hot weather or when exercising or standing for a long time.
Some diuretics make the skin more sensitive to sunlight. Even brief exposure to sun can cause a severe sunburn, itching, a rash, redness, or other changes in skin color. While being treated with this medicine, avoid being in direct sunlight, especially between 10 a.m. and 3 p.m.; wear a hat and tightly woven clothing that covers the arms and legs; use a sunscreen with a skin protection factor (SPF) of at least 15; protect the lips with a sun block lipstick; and do not use tanning beds, tanning booths, or sunlamps. People with fair skin may need to use a sunscreen with a higher skin protection factor.

Special conditions

People who have certain medical conditions or who are taking certain other medicines may have problems if they take diuretics. Before taking these drugs, be sure to let the physician know about any of these conditions:

Pregnancy

Diuretics will not help the swelling of hands and feet that some women have during pregnancy. In general, pregnant women should not use diuretics unless a physician recommends their use. Although studies have not been done on pregnant women, studies of laboratory animals show that some diuretics can cause harmful effects when taken during pregnancy.

Breastfeeding

Some diuretics pass into breast milk, but no reports exist of problems in nursing babies whose mothers use this medicine. However, thiazide diuretics may decrease the flow of breast milk. Women who are breastfeeding and need to use a diuretic should check with their physicians.

Use of certain medicines

Taking diuretics with certain other drugs may affect the way the drugs work or may increase the chance of side effects.

Side Effects

Some side effects, such as loss of appetite, nausea and vomiting, stomach cramps, diarrhea and dizziness, usually lessen or go away as the body adjusts to the medicine.
These problems do not need medical attention unless they continue or interfere with normal activities.
Patients taking potassium-sparing diuretics should know the signs of too much potassium and should check with a physician as soon as possible if any of these symptoms occur:

Irregular heartbeat
Breathing problems
Numbness or tingling in the hands, feet or lips
Confusion or nervousness
Unusual tiredness or weakness
Weak or heavy feeling in the legs.

Patients taking diuretics that cause potassium loss should know the signs of too little potassium and should check with a physician as soon as possible if they have any of these symptoms:

Fast or irregular heartbeat
Weak pulse
Nausea or vomiting
Dry mouth
Excessive thirst
Muscle cramps or pain
Unusual tiredness or weakness

Mental or mood changes.
Interactions

Diuretics may interact with other medicines. When this happens, the effects of one or both of the drugs may change or the risk of side effects may be greater. Anyone who takes a diuretic should let the physician know all other medicines he or she is taking and should ask whether the possible interactions can interfere with drug therapy. Among the drugs that may interact with diuretics are:
Angiotensin-converting enzyme (ACE) inhibitors such as benazepril (Lotensin), captopril (Capoten) and enalapril (Vasotec), used to treat high blood pressure. Taking these drugs with potassium-sparing diuretics may cause levels of potassium in the blood to be too high, increasing the chance of side effects.
Cholesterol-lowering drugs such as cholestyramine (Questran) and colestipol (Colestid). Taking these drugs with combination diuretics such as Dyazide and Maxzide may keep the diuretic from working. Take the diuretic at least 1 hour before or 4 hours after the cholesterol-lowering drug.
Cyclosporine (Sandimmune), a medicine that suppresses the immune system. Taking this medicine with potassium-sparing diuretics may increase the chance of side effects by causing levels of potassium in the blood to be too high.
Potassium supplements, other medicines containing potassium, or salt substitutes that contain potassium. Taking these with potassium-sparing diuretics may lead to too much potassium in the blood, increasing the chance of side effects.
Lithium, used to treat bipolar disorder (manic-depressive illness). Using this medicine with potassium-sparing diuretics may allow lithium to build up to poisonous levels in the body.
Digitalis heart drugs, such as digoxin (Lanoxin). Using this medicine with combination diuretics such as triamterene-hydrocholorthiazide (Dyazide, Maxzide) may cause blood levels of the heart medicine to be too high, making side effects such as changes in heartbeat more likely.

The list above does not include every drug that may interact with diuretics. Check with a physician or pharmacist before combining diuretics with any other prescription or nonprescription (over-the-counter) medicine.