Hormone, adrenal cortex androgenic

Adrenal hormone production is controlled by the hypothalamus and pituitary gland. Corticotropin-releasing hormone (CRH) is secreted by the hypothalamus and stimulates secretion of adrenocorticotropic hormone (ACTH), also known as corticotropin from the anterior pituitary. ACTH, in turn, stimulates the adrenal cortex to produce cortisol. When sufficient or excessive cortisol levels are reached, a negative feedback is exerted on the secretion of CRH and ACTH, thereby decreasing overall cortisol production. The control of adrenal androgen synthesis also follows a similar negative-feedback mechanism. 

The interaction between the adrenal cortex of the foetus and the placenta in production of steroid hormones is complex. In outline, the placenta produces progesterone from cholesterol (which is available from the maternal blood) whereas the foetal adrenal cortex produces corticosteroids and androgens from the progesterone produced in the placenta. The placenta then converts some of these androgens into oestrogens. The interplay between the placenta and the foetal adrenal cortex is acknowledged by the use of the term foeto-placental unit to describe steroido-... 

AdrenocorticotrophicAnterior Stimulates adrenal cortex to secrete hormone (ACTH) pituitary glucocorticoids, mineralocorticoids, and Melanocyte- androgens stimulates melanocytes ... 

Adrenocorticotropin (ACTH) Corticotropin-releasing hormone (CRH)(+) Adrenal cortex Glucocorticoids, mineralocorticoids, androgens... 

Steroid hormones are secreted on demand from their tissues of origin in response to hormonal signals. The corticosteroids and androgens are made in different regions of the adrenal cortex, and are secreted into blood in response to different signals. 

The primary function of AC. TH is the stimulation of the adrenal cortex to produce its hormones, which have already been discussed. This is evideni from the therapeutic effect of administration of ACTH. which is closely similar to that of Ihese hormones, so that if ihe action of only one of them is sought, its administration is preferable, Moreover. ACTH stimulates secretion of the androgenic substances mentioned as produced by the adrenal cortex. 

The adrenocorticotrophic hormone ACTH (corticotropin) stimulates the adrenal cortex to secrete the glucocorticoids hydrocortisone (cortisol) and corticosterone, the mineralocorticoid aldosterone, and a number of weakly androgenic substances, as well as a small amount of testosterone. Aldosterone synthesis is also regulated by renin and angiotensin. 

Hormones of the Adrenal Cortex. The adrenal cortex synthesizes and secretes two primary groups of steroidal hormones the glucocorticoids and the min-eralocorticoids.41 Small amounts of sex steroids (estrogens, androgens, progesterone) are also produced, but these amounts are essentially insignificant during normal adrenal function. 

This chapter discusses the pharmacology of the steroid hormones that are produced by the adrenal cortex. The two primary types of adrenal steroids are the glucocorticoids and mineralocorticoids. Small amounts of other steroids such as the sex hormones (androgens, estrogens, and progestins) are also produced by the adrenal cortex. These steroids are discussed in Chapter 30. 

Male and female hormones are produced primarily in the gonads. Androgens are synthesized in the testes in the male. In the female, the ovaries are the principal sites of estrogen and progestin production. As discussed in Chapter 29, small amounts of sex-related hormones are also produced in the adrenal cortex in both sexes, which accounts for the fact that small amounts of hormones of the opposite sex are seen in females and males that is, low testosterone levels are seen in females, and males produce small quantities of estrogen. However, under normal conditions, the amounts of sex-related hormones produced by the adrenal cortex are usually too small to produce significant physiologic effects. 

ACTH stimulates the adrenal cortex to produce glucocorticoids, mineralocorticoids, and androgens. ACTH increases the activity of cholesterol esterase, the enzyme that catalyzes the rate-limiting step of steroid hormone production cholesterol - pregnenolone. ACTH also stimulates adrenal hypertrophy and hyperplasia. When given chronically in pharmacologic doses, corticotropin causes increased skin pigmentation. 

Q2 The adrenal cortex secretes three main groups of hormones mineralocorticoid (e.g. aldosterone), glucocorticoids (e.g. cortisol, cortisone and corticosterone) and gonadocorticoids (mainly androgens with small amounts of progesterone and oestrogen). Aldosterone is a salt-retaining hormone which acts on the kidney to facilitate sodium and water reabsorption. 

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