Approximately 50% of testosterone is metabolized via conjugation into testosterone glucuronide and to a lesser extent testosterone sulfate by glucuronosyltransferases and sulfotransferases, respectively. The amount of testosterone synthesized is regulated by the hypothalamic–pituitary–testicular axis (Figure 2). In addition, the amount of testosterone produced by existing Leydig cells is under the control of LH, which regulates the expression of 17β-hydroxysteroid dehydrogenase. Serious side effects may include liver toxicity, heart disease (though a randomized trial found no evidence of major adverse cardiac events compared to placebo in men with low testosterone), and behavioral changes. Testosterone is used as a medication for the treatment of male hypogonadism, gender dysphoria, and certain types of breast cancer. As demonstrated by a meta-analysis, substitution therapy with testosterone results in a significant reduction of inflammatory markers. Attention, memory, and spatial ability are key cognitive functions affected by testosterone in humans. Conflicting results have been obtained concerning the importance of testosterone in maintaining cardiovascular health. In AIS, gender identity usually follows the sex of rearing, but quality of sexual life, sexual functioning and quality of life can be slightly compromised and are important issues for keeping patients in psychological care. Fertility was described in one PAIS individuals, and therapeutic strategy for successful fertility could be experienced in PAIS and MAIS individuals. For males with PAIS, the testis should be placed in the scrotum and regularly monitored. In CAIS, there is a low risk of GCTs before puberty and postponing surgery to after puberty may allow the development of spontaneous puberty. As an adult, your body converts about 10% of your testosterone (the main androgen) into DHT each day. They named the hormone testosterone, from the stems of testicle and sterol, and the suffix of ketone. A testicular action was linked to circulating blood fractions – now understood to be a family of androgenic hormones – in the early work on castration and testicular transplantation in fowl by Arnold Adolph Berthold (1803–1861). Greatly differing amounts of testosterone prenatally, at puberty, and throughout life account for a share of biological differences between males and females. Only the free amount of testosterone can bind to an androgenic receptor, which means it has biological activity. Specific proteins include sex hormone-binding globulin (SHBG), which binds testosterone, dihydrotestosterone, estradiol, and other sex steroids. The rise in testosterone during competition predicted aggression in males, but not in females. Higher pre-natal testosterone indicated by a low digit ratio as well as adult testosterone levels increased risk of fouls or aggression among male players in a soccer game. The same research found fathers (outside competitive environments) had the lowest testosterone levels compared to other males.
