Реферат: Steroids Essay Research Paper Testosterone was often
Название: Steroids Essay Research Paper Testosterone was often Раздел: Топики по английскому языку Тип: реферат |
Steroids Essay, Research Paper Testosterone was often referred to as the "male" hormone, because it is responsible for developing some of the male characteristics such as lowering of the voice and hair growth, and because the male body produces much more of it than the female. However, it is responsible for stimulating quite a few other processes. Steroids are a very large class of compounds which occur in all animals. The steroids used by athletes are mostly androgenic steroids: steroids which act like testosterone. The steroids used to treat inflammatory disorders (e.g. prednisolone, cortisone,beclomethasone, budesonide, dexamethasone and dozens of others) are cortico steroids and do not have anabolic effects. Testosterone in the male is produced mainly in the testis, a small amount being produced in the adrenal. It is synthesized from cholesterol. The regulation of its production may be simplified thus: the hypothalamus(part of the brain) produces gonadotrophin releasing hormone (GnRH) which acts on the anterior pituitary to increase the production of luteinizing hormone (LH) and follicle stimulating hormone (FSH). LH acts on the Leydig cells in the testis, causing them to produce testosterone. FSH, together with testosterone act on the Sertoli cells in the testis to regulate the production and maturation of spermatozoa. Testosterone in turn acts on thehypothalamus and anterior pituitary to suppress the production of GnRH, FSHand LH, producing a negative-feedback mechanism which keeps everything well-regulated. The small amount produced in the adrenal (in both sexes) is regulated by secretion of adrenal corticotrophic hormone (ACTH), also secreted by the pituitary. Testosterone, and its metabolites such as dihydrotestosterone, act in many parts of the body, producing the secondary sexual characteristics ofthen male: balding, facial and body hair, deep voice, greater muscle bulk,thicker skin, and genital maturity. At puberty it produces acne, the growth spurt and the enlargement of the penis and testes as well as causing the fusion of the epiphyses (through its conversion to estrogen), bringing growth in height to an end. It plays some role in maintaining the sexualorgans in the adult, but only a low concentration is required for this. The normal production of testosterone in the adult male is 4 to 9mg per day. The normal plasma concentration is 22.5nmol/l, of which 97% is protein bound. Most is excreted in the urine as 17-keto steroids, but a small amount is converted to oestrogens. Various analogs of testosterone are used in medical treatment of testicular failure,hereditary angioedema, anemia, severe endometriosis and a few other conditions. Testosterone itself is given by injection. Oral preparations such as methyltestosterone, fluoxymesterone, mesterolone andstanolone are sometimes used, but they cause substantially more liverdamage than injectable or rectally administered preparations because they are absorbed from the gut and transported first to the liver (like most things taken by mouth)where they reach quite high concentrations and are extensively metabolized before circulating to the rest of the body. in both the male and female body, such as skin, muscle and bone. Anabolic steroids are synthetic versions of testosterone, they are steroid hormones that are claimed to have a greater anabolic effect than virile. the testosterone molecule has in different ways been altered to lessen the androgenic effects and increase it’s protein build-up abbility, and preferably eliminate it’s masculine enhancing features. Unfortunately this has not been completely successful, so there are a lot of different side effects with any anabolic steroid. Steroids was developed in the 1940s in Germany and used experimentally on their troops during World War II, the drugs ability to stimulate tissue growth and protein synthesis lead them to believe that the drug might be beneficial to treat burn victims and towards other war accidents. The drug was never such a big success, because other drugs with fewer side effects were discovered, and the legal use of steroids still seems to be declining.Steroids are used for treating anaemia, because of it’s abbility to increase the production of red blood corpuscles (red blood cells). They are also used for treatment of leukemi, cancer mammae, and at times steroids are also used for general strengthening therapy. Steroids have also been tried in combination with other drugs as a means of helping AIDS pasients.It’s no secret that athletes often use steroids to stay at the top, unfortunately it seems as if it is not possible to dominate in some sports without the aid of drugs like steroids. Steroids can without doubt increase muscular growth in women and children but there is still some dispute on whether steroids work for grown up men. Still, a vast number of athletes and trainers are convinced that steroids causes muscular growth and increases the body’s ability to recuperate after hard training. This might very well be true, but for these effects the doses need to be pretty high, causing greater side effects. Side effects that might occur: Sterility Liver damage and pain Kidney damage and pain Heart damage/problems/disease/irregularities/strokes Hypophysis supression High blood pressure (Hypertension) Acne Cancer Shrunken testicles Neanderthale-look, a big jaw-bone and spacing between teeth Higher risk of injury because of strain on tendons and joints Water retention Baldness (male) Prostrate enlargement Aggressive behavior (’roid rage) Depression Gynecomastia Lowered sperm count Temporarily raised sex drive when on steroids and almost eliminating it later.Be aware that some steroid side effects are not reversible Women should take even more caution using steroids since their normal levels are only 5% of the average male’s testosterone level. Women may get most of the above mention side effects but might have more trouble with the following: Lowering of the voice Increased fascial and body hair growth Reduced breast size Acne Genital enlargement Menstrual cycles Well, some of the side effects of using steroids are reversible, but far from all of them. However, once you get off steroids you might loose almost all the gains you made while being on them. This might be due to the fact that your body shuts down the production of it’s own testosteron when supplied with large amounts of synthetic testosteron in the form of steroids. Some bodybuilders claim that it is possible to kickstart your body’s production of testosterone by using certain drugs after getting off steroids. Depression is often experienced, self esteem drops and the desire to train as well. Sometimes people stop cycling steroids because they don’t manage to get off the drugs for a month or two. Injectable steroids are longer lasting in the body, but therefore they can be detected in your body for a longer periode of time, so athletes that are likely to be doping tested have shifted from using injectables to orals. The problem with orals however, aside from the fact that they are not as long lasting, is that they put a lot of strain on the liver as they must be processed there. Larger quantities are also needed as a lot of it is broken down before it enters the bloodstream. How can You tell if someone is using Steroids? If he has some of these symptoms he might be on steroids: Rapid weight and muscle gain Sudden mood changes and aggressive behavior Acne, especially on the back Trembling Sudden increase of food consumption Enhanced recuperation / Reduced recovery time Strength increases Reduced bodyfat Enlarged muscle size Many of these effects are only temporary, which means that once you get off steroids most of the gains disappear. As mentioned before steroids causes water retention, so steroid users will gain mass very quickly, but most of it will be water not muscles. This will put the body through a lot of stress, loosing and gaining weight in cycles. The more positive sides of steroids are that they seem to be able to suppress the body’s production of the stress hormone cortisol after exercise. Cortisol is actually a muscle tissue destroyer, so by keeping the levels of cortisol down reduces muscle damage and allows for faster recuperation. So the steroid user might be able to train more frequent. Another major effect of steroids is the increased stimulation of the protein synthesis by increasing the amount of nitrogen in the body, more protein available to the body means that the environment for muscle production is better. A lot of steroid users report that the steroids help them lower their body fat levels, the reason for this is not clear, but some feel it is because of an increased metabolic rate. Others claim that oxidation of fat is increased because the steroids promote mitochondria growth in the cells. What if You don’t exercise, but take steroids, will you experience muscle gains? Yes, in fact you might experience muscle growth, but this growth will be much less than what is achieved together with training. Steroids will mostly help your body to recuperate faster thus enabling you to train longer and harder. But will also build muscles by stimulating the protein synthesis and keeping the production of the stress hormone cortisol down. Cancers of the prostate are frequently dependent on testosterone(hence their treatment by castration) and they may progress very rapidly in the presence of high level of androgens. A percentage of testosterone is converted to estrogen and some artificial androgens have some estrogen effect as well, causing enlargement of the breast tissue behind the nipple (gynaecomastia). This is occasionally seen naturally in pubescent boys and a small percentage of the adult male population. This effect may be reduced by drugs which inhibit the binding of estrogen to its receptors: e.g.clomiphene, cyclofenil and tamoxifen or drugs that block the enzyme,aromatase, that converts testosterone to estrogen. So are they safe? The approval and use of any drug is a matter of deciding whether the therapeutic benefits from its use are worth the adverse effects. No drug is safe; acetaminophen (paracetamol) causes some verynasty fatal poisonings, aspirin causes rare cases of devastating skinreactions. Problems occur with every pharmaceutical and it is usually dose dependent. However, the concensus is that they save enough lives and alleviate enough problems to more than compensate for the bad effects. In therapeutic doses, steroids result in few side effects. Androgenic steroids have a fairly limited use in medicine. They are effective in males with testicular failure and are occasionally used inosteoporosis and as an appetite stimulant in severely wasted patients. In the past they were also used to treat anemia, however, more effective treatements now exist for this disease. In these cases the benefits clearly outweigh the risks for the patient. Using them for essentially cosmetic or frivolous reasons doesn’t produce much of value to compensate for the risks associated with their abuse. Using drugs under medical supervision doesn’t make the drugs any safer, it just gives a greater chance that the adverse effects may be picked up sooner, and it decreases the chances that an abusive quantity will be used. What Side effects are commonly seen with steroid use? First, there are many different anabolic steroids and based on how the body handles them, they have very different side effects. Some steroids have virtually no side effects and to lump all anabolic steroids into one category (in terms of benefit or harm) shows a lack of understanding with respect to their pharmacological action. In therapeutic doses, 100 mg deca-durabolin per week for example, very fewside effects are observed. Unfortunately, most athletes will not restrict their use to therapeutic doses. What happens when athletes take some of the harsher anabolic steroids in abusive dosages? Numerous side effects can result while on steroids including acne, increased sex drive, impotence, liver problems, aggression and psychological dependence. Other side effects, including gynecomastia, high blood pressure, other cardiovascular diseases, baldness, stunted growth in adolescents, and enlargement of pre existing prostate tumors can persist even after steroid use has stopped. Female steroid users, in addition to the problems listed above, can have virilizing(masculinizing) symptoms when using the harsher, androgenic compounds,including amenorrhea (which is reversible), clitoral hypertrophy, deepervoice, excessive growth of body hair, loss of scalp hair and alterations in skin texture (which frequently aren’t reversible). Not all of these conditions are caused by all anabolic steroids. Some of the harsher anabolic steroids will only cause these problems for a certain percentage of the users, above certain dosages. Some of the milder anabolic steroids cause almost none of these side effects. There fore, it is a mistake to state that all steroid users will come down with these side effects. Any such silly statements will be readily flamed on m.f.w. Most of the sideeffects of steroid use result from the conversion of testosterone to estrogen or dihydrotestosterone. Some anabolic steroids do not undergo this conversion. These steroids will have fewer side effects. 317 |