Biochemistry Extra Credit Paper
Estrogen and Its Effects
Estrogens are steroids that are important in the reproductive cycles of humans and some animals, and they are the main female sex hormones. They easily diffuse across cell membranes, and once they are inside, they bind to estrogen receptors to control many genes and their expressions. In human women, there are three types of estrogen: estradiol, which is the dominant form of estrogen in women who are not pregnant, estrone, which is produced during menopause, and estriol, which is found in pregnant women. Estradiol is the most potent of the three types of estrogen found in women, almost ten times stronger than estrone and almost eighty times stronger than estriol. It has a very important impact on the reproductive cycle and sexual development in both women and men alike, but it is not only critical for sexual functions, however; it also affects many other organs, specifically including the bones and the heart. Without estradiol, the risk of cardiovascular disease increases exponentially, especially in women who have reached menopause, and bone structure and density is affected negatively as well. For years, studies have shown that post-menopausal women have greater risk of having osteoporosis; this is because their levels of estradiol are reduced once menopause hits. The major purpose of estrogen in bones is to regulate osteoblast apoptosis, or death of the cells that are responsible for forming bone, and therefore regulate the breakdown of bone and release of minerals to the bloodstream. With deficiency of estrogen, the osteoblasts live longer and can break down more bone than they normally would, thus leading to loss of bone and tearing of the trabecular plates, which are spongy plates found at the ends of long bones such as those in the leg or arm. This was proven in a study done in 1990 done by Yamamoto and Rodan in West Point, Pennsylvania. They used an experimental...
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