The main signaling molecule of the sex hormones is testosterone. The testosterone is usually converted to dihydrotestosterone, which is a more potent hormone. In addition to dihydrotestosterone, testosterone can also be converted to estradiol by the enzyme P450 aromatase. Testosterone is a steroid hormone from the androgen group. The male and female bodies both produce testosterone however men produce about forty to sixty times more testosterone than women. Testosterone is produced in the testes in the male body and in the ovaries in the female body. Testosterone is responsible for the maturation of sex organs in the male body. Estrogen, the female sex hormone is important for the maturing of sex organs and the hormonal balance in women. This study also reveals that testosterone plays a key role in preventing osteoporosis. Estrogen has also been found to assist in longitudinal bone growth.
The article discusses how mutation in the signaling receptor causes a disorder called aromatase-deficiency. Aromatase-deficiency is the result of a mutation ER-alpha or the total loss of estrogen synthesis due to a mutation on the aromatase gene. It is a mutation of CYP19A1 and all cases to date are heterozygous for the mutation. The result is these males have undetectable estrogen levels and have severe osteopenia (a condition where bone mineral density is lower than normal) and still-open epiphyses (the rounded end o a long bone), despite normal or elevated testosterone levels as well as they did not have growth spurts. However, when estrogen was administrated the bone mass of these men increased significantly. The estrogen also induced epiphyseal closure and longitudinal growth in these patients.
Normally the signaling molecule, testosterone, would be converted into 17-beta estradiol by P450 aromatase and subsequently activate estrogen receptor by binding to it. In the case of aromatase-deficiency this process can be disrupted in to different ways. The first case testosterone is still turned into 17-beta estradiol, but because of the mutation in ER-alpha receptor the testosterone signaling molecule cannot bind to the receptor meaning estrogen receptor will not be activated and no estrogen will be produced. The second case there is a mutation in the aromatase gene that converts testosterone to 17-beta estradiol, this means that the testosterone will not be converted to the proper signal. Therefore, there will not be a signal to activate the estrogen receptor meaning that estrogen will never be made.
This article is interesting because it is not a disorder. It shows that sex steroids are instrumental in not only proteins and sex maturation, but in bone health and growth. The article shows how steroid hormones can affect many aspects of the body. The hormones are so different than the bones and it is very interesting that the steroid hormones can have a significant effect on them.
Works Cited
Aromatase Deficiency. Gene Dx. Web. 15 Nov. 2009. <http://www.genedx.com/services/dis_cypa.php>.
Epiphysis. Wikipedia FoundationInc, 6 June 2009. Web. 15 Nov. 2009. <http://en.wikipedia.org/wiki/Epiphysis>.
Osteopenia. Wikipedia Foundation Inc., 19 Sept. 2009. Web. 15 Nov. 2009. <http://en.wikipedia.org/wiki/Osteopenia>.