Findings of a recent study undertaken by researchers in Canada have suggested that the foul odor of gas generated in the alimentary canal or flatulence may perhaps have a crucial task in controlling blood pressure. In both cases, the gas is hydrogen sulphide - a toxic substance.
The findings of the research published in the recent edition of the journal titled 'Science' states that it has been found that when the hydrogen sulphide produced by bacteria in the human intestines is released, it calms down the blood vessels facilitating the blood circulation throughout the body.
According to Rui Wang, a physiologist at the Lakehead University at Thunder Bay in Ontario, it is difficult to overrate the biological significance of hydrogen sulphide or the gas' inference vis-à-vis high blood pressure or hypertension. In fact, Wang has prepared the research paper along with Lingyun Wu, a pharmacologist at the University of Saskatchewan, and other researchers and scientists from the Johns Hopkins Medical School located in Baltimore.
It may be mentioned here that the study was conducted on mice over a period of five years. During the research, scientists discovered that an enzyme known as CSE generated the gas or hydrogen sulphide in the cells coating the walls of the arteries and veins passing all over the body. In fact, the results of the study conducted by the Canadian researchers corroborated the findings of a previous research that put forward the theory regarding a connection between the enzyme and the gas or flatulence.
During the course of the research, the scientists propagated and brought up mice that had CSE levels much below the normal intensity of the enzyme. In due course, the scientists discovered that the mice bred by them possessed considerably lesser levels of hydrogen sulphide as compared to the normal animals with typical CSE intensity. At the same time, the scientists detected that the mice suffering from insufficient CSE had higher blood pressure. To be precise, when compared with the normal animals, the mice with lower CSE levels had 20 per cent higher blood pressure.
Interestingly enough, when the engineered mice that had lesser CSE intensity were administered a drug called methacholine, their blood pressure was found to be more or less similar to those mice which possessed the usual levels of CSE. Incidentally, methacholine is a medicine normally administered to people to calm down their blood vessels. Following this finding, the researchers suggested that hydrogen sulphide - the gas produced by bacteria in the intestinal tract - was accountable for the change in the blood pressure in most animals as also the humans. The authors of the research findings published in the journal 'Science' further hinted that their research results may prompt new methods of treatment for controlling blood pressure in humans.
In a press release issued by the Johns Hopkins University, Dr. Solomon H. Snyder, a neuroscientist associated with the university who also co-authored the findings of the research by Canadian scientist, asserted that now that it has been established that hydrogen sulphide is responsible for controlling blood pressure, it will enable researchers to develop new medications that will facilitate the formation of the gas in the intestines. He said that the findings of the research are significant as they would definitely lead to new and alternative methods for treating hypertension or high blood pressure.
This is a colorless gas having a distinctive rotten egg smell when used in low concentration. Most people are exposed to hydrogen sulfide (H2S) through breathing. This gas is produced when organic substances (which were living earlier) decomposes or in the form of a by-product in several industrial processes. Compared to air, hydrogen sulfide is somewhat heavier and, hence, it is particularly considered to be dangerous for people residing in low-lying regions and also for those who are working in enclosed or confined spaces. Hydrogen sulfide has an explosive reaction when it is kept in very high temperatures, for instance, as 500°F or 260°C.
Hydrogen sulfide is known by several different names, for instance, sulphur hydribe, dihydrogen sulfide, sulfuretted hydrogen, hydrosulphuric acid and also hepatic gas. Commonly, hydrogen sulfide is also known as sewer gas, stink gas or sour gas.
Hydrogen sulfide (H2S) is considered to be a lethal poison. When an individual breathes in this gas, it passes to the lungs, from where it is transferred to the bloodstream. In such situations, the body tries to protect itself from this harmful gas by breaking down the hydrogen sulfide into harmless chemicals without any delay. Hydrogen sulfide results in poisoning only when the quantity of the gas taken up by the bloodstream is more than the amount that the body is able to get rid of.
When one is exposed to high levels of hydrogen sulfide (also known as acute exposure), the individual may go into coma or even die owing to the failure of the respiratory system. In addition, hydrogen sulfide may also accumulate in the bloodstream, thereby paralyzing the nerve centers located inside the brain. Subsequently, this may result in the non-functioning of the nerves. Unless, the condition is detected timely, the severe or acute exposure to the gas may prove to be lethal.
Exposure to comparatively less concentrated hydrogen sulfide (a condition known as sub-acute exposure) may also make the person experience a number of adverse effects, such as headaches, light-headedness, and nausea, lack of balance, agitation and even diarrhea. Continuous exposure to low concentration of hydrogen sulfide (also known as chronic poisoning) may cause exhaustion, slackened pulse rate, cold sweat, weight loss, infections in the eyes and skin eruptions. In case any worker is having any of the above mentioned symptoms, it is may be an indication of poisoning due to exposure to hydrogen sulfide. In such cases, it is possible that hydrogen sulfide is present in the worker's bloodstream. Therefore, it is important for the individual to undergo a test to determine if the gas has actually accumulated in his/ her bloodstream and in case the results of the diagnosis are positive, he/ she should be given appropriate treatment.
The cells present in a number of mammals produce very little amounts of hydrogen sulfide and this gas has several functions, especially biological signalling, in their body. As of now, scientists are aware of two more similar gases - carbon monoxide (CO) and nitric oxide (NO).
Inside the body of some mammals, the enzymes called cystathionine gamma-lyase and cystathionine beta-synthase produce hydrogen sulfide from cysteine. This gas works to relax or unwind the smooth muscles and also in the form of a vasodilator (expansion of the blood vessel walls). In addition, hydrogen sulfide has been found to be active inside the brain, where this gas enhances the NMDA receptors' response, while facilitating enduring potentiation that is necessary for the development of memory.
In due course, thiosulfate reductase present in the mitochondria changes hydrogen sulfide into sulfite, which is oxidized further by sulfite oxidase to form thiosulfate and sulfate. Finally, these products are removed from the body through urination.
As the effects of hydrogen sulfide are akin to those of nitric oxide (NO), but lacking the potential of the latter to form peroxides due to interaction with superoxide, scientists have now recognized this gas as a substance that may possibly help to protect us against or prevent cardiovascular ailments. Garlic also works to protect the cardiovascular system and the mechanism involved in this is catabolism or breaking down substances belonging to the polysulfide group to simpler substances like hydrogen sulfide in allicin. In fact, this chemical reaction possibly depends on glutathione's mediating capacity to reduce.
While hydrogen sulfide (H2S) as well as nitric oxide are both capable of relaxing the blood vessels, their mechanisms differ greatly. NO or nitric oxide works to activate the enzyme known as guanylyl cyclase, while hydrogen sulfide works to turn on potassium channels sensitive to ATP in the smooth muscle cells. However, scientists still do not clearly understand the manner in which the hydrogen sulfide and nitric oxide share their responsibilities to relax the blood vessels. Nevertheless, they have some proof that hint at the fact that nitric oxide is actually responsible for majority of the work related to relaxing the blood vessels, while hydrogen sulfide performs the same task in other blood vessels that are comparatively small.
Some latest scientific discoveries hint at a powerful cellular crosstalk involving hydrogen sulfide (H2S) and nitric acid (NO), revealing that both these gases are excellent vasodilators and they are dependent on one another in fulfilling this responsibility. In addition, hydrogen sulfide has an intercellular reaction with S-nitrosothiols to produce the minutest S-nitrosothiol (HSNO). In addition, the findings suggest that hydrogen sulfide also plays a role in regulating the pool of intracellular S-nitrosothiol.
Similar to nitric oxide (NO), hydrogen sulfide (H2S) too is engaged in relaxing the smooth muscles that are responsible for the penis becoming erect. Therefore, this finding presents the scientists with novel remedial prospects for erectile dysfunction (ED).
The concentration of hydrogen sulfide within the brain decreases considerably in people with Alzheimer's disease. It was found that the level of hydrogen sulfide in the brain was lessened in a specific rodent model related to Parkinson's disease and the condition alleviated when these rats were given hydrogen sulfide. On the other hand, the body of people with Down syndrome (trisomy 21) produces surplus hydrogen sulfide (H2S). In addition, it has been found that hydrogen sulfide has a role in the progress of type 1 diabetes. In the case of this disease, the beta cells present in the pancreas produce excessive hydrogen sulfide, which results in the elimination of these cells and those that still remain produce very little insulin, thereby helping the disease to progress.