Androgens are a set of hormones that basically impacts the development and growth of the reproductive system of males. The testosterone is the most dynamic and domineering androgen, which gets generated by the man’s testicles.. The relatively lesser amount of supplementary androgens that support the working of testosterone is primarily generated through the exterior part of the adrenal gland, called the adrenal cortex.
In men, the Leydig interstitial cells, which are found in the connective tissue around the sperm-generating tubules of the testicles, are accountable for the generation and discharge of testosterone. Among male birds and animals, in which the breeding happens seasonally, like sheep and migratory birds, the Leydig cells are found in the testicles in the season of breeding but begin lessening significantly in the non-breeding period. These cells, actually, control the release of androgens through the luteinizing hormone (LH) secreted by the pituitary gland.
The androgens produced by the adrenal cortex are vital for many physiological procedures. Some androgens generated by adrenal gland – dehydroepiandrosterone and androstenedione, dehydroepiandrosterone sulfate (DHEA sulfate) – are convertible to testosterone in some other cells.
Physiological impact of Androgens in men
A very little quantity of androgen is released before the onset of puberty. Puberty is linked to the increased adrenal androgen generation in both boys and girls. This increased production of adrenal androgen helps in attaining pubertal maturity and the development of pubic hair and other sexual characteristics.
Androgens are also required for developing the reproductive system of males. Men, who get castrated before the adolescence or attaining adulthood need testosterone injections for developing the reproductive organs functioning. With the aid of androgens, the size of reproductive appendages gets increased in men. Contrarily, the castration done on men, after reaching the level of maturity makes the size their organs reduced and prevent their functioning. Androgens are also required for the generation of sperm in the semen and maintaining the sexual behavior and interest.
There are diversified effects of androgens on the bodies of men. The development of pubic hair, chest hair and facial hair and the waning hair on the scalp and baldness are impacted by androgens. In adolescent, androgens thicken and lengthen the vocal cords of boys resulting in deepening voice.
Besides, the androgens increase the growth of bones and their density, and enhance the muscle fiber thickness in boys. Some other growth sequences that androgens help in simulating are the size and weight of kidneys, the enhanced protein in bone tissues, the redevelopment of red cells in the blood, the existence of skin pigments and the higher activity of sebaceous and sweat glands.
Excessive amount of androgen in females
Compared to males, the females generate around 1/12th Androgen as men. Androgens are indispensable forbears of estrogens, and they cannot be generated without androgens. The physiological bearing of androgens in females is not very clear.
Some studies advocate that the androgens evidence suggests that androgens help in the growth of libido and bones. A small amount of excessive androgen in females causes unnecessary growth of hair all over their body that can be seen on the face. The condition is called hirsutism.
With the higher amount of excessive androgen in females, their periods get abnormal (oligomenorrhea) and finally stop causing a condition amenorrhea, and virilizing the females. The perceptible virilizm may include voice deepening, balding from the front, clitoral bulge, acne and higher mass in the muscles.
In females, the ovaries generate nearly 50 percent of androgen in the shape of testosterone and less dynamic androstenedione. The rest of it is generated by the adrenal glands, mostly in the form of DHEA sulfate and DHEA that get transformed into testosterone and androstenedione in other cells. This convertible capability is present in the brain, muscle, fat and skin tissues. A few of these tissues have the capability of transforming androstenedione into more powerful testosterone. A certain amount of testosterone generated in this manner comes back to the circulation to work at far-away places, but a high amount may get accumulated in the in some special areas, like follicles of hair.
In females, excessive generation of androgen may cause disorders in their ovaries, adrenal glands, and other disorders like in fat and non-endocrine cells. The excessive generation of androgens may result in Congenital Adrenal Hyperplasia, Adrenal tumors, and even Cushing Syndrome. Though rarely, the tumors and even cancer in the interstitial cells and some other ovarian cells may cause excessive generation of androgen in females.
Polycystic Ovary Syndrome (PCOS), also known as Stein-Leventhal Syndrome, also commonly causes excessive generation of androgens in females. The syndrome is distinguishable by the presence of irregular periods and excessive androgens. Excessive androgen very often is evident in the excessive hairiness (hirsutism), without or with higher serum accumulation of 1 or more androgens. Some females experience higher serum androgen accumulation yet no occurrence of hirsutism.
An ultrasound scan may detect the possibility of multiple cysts on the ovaries. The syndrome is usually found in the obese females. Another typical PCOS feature is resistance to the effect of insulin. This is generally found in the obese females, but, at times, the syndrome is also found in the non-obese females. The insulin resistance causes higher amount of insulin discharge and this condition is known as hyperinsulinemia. Hyperinsulinemia is, sometimes, is presumed to stimulate generation of androgen and linked to the diabetes. The condition also declines the generation of globulin, which is a compulsory for sex hormones and makes the testosterone available in the serum so that it is accessible and free for the tissues.
Apart from this, the transformation of androgens in the adipose tissue to estrogens becomes higher, especially in obese females. This helps in a higher amount of luteinizing hormone secretion and suppressing the ovulation (when ovulation does not happen in a female, it is known as anovulation).