ANDROGENS

1. M.Prasad Naidu MSc Medical Biochemistry, Ph.D.Research Scholar ANDROGENS

2. Male sex hormones • Androgens or androgenic hormones • Testosterone, androsterone, dehydroepiandrosterone • Androsterone is the first to be isolated • The main commercial source of androgens: urine of male , female and testicular extract • Androgens also produced in A. Cortex • Testosterone is the most potent

3. Biosynthesis • Cholesterol • Testis, adrenal gland & ovary • Production & release stimulated by : ICSH • Acetate  Cholesterol  pregnolone  progesterone  testosterone

4. Metabolism • Liver • Principal metabolites: 17-ketosteroids • 17-KS give colour reactions such as Zimmermann (m-dinitrobenzene) and Pincus ( antimony trichloride) reactions • 17-KS are of 2 types • 1. neutral and acidic

5. Reactions involved in androgen metabolism • 1. conversion of C17 –OH group to the keto group • 2. reduction of 4,5 double bond • 3. reduction of ketonic group at C3 • 4. conjugation with glucuronic acid or sulphuric acid • Most imp 17-KS isolated from urine are androsterone, etiocholanolone, dehydroepiandrosterone, epiandrosterone. • The amt of 17-KS increases with age and in pregnancy

6. Metabolism • Abnormally high 17-KS are found: in increased adrenocortical function, increased interstitial cell function • Slight increase of 17-KS found in: acute illness, starvation, anoxia, physical or mental stain, exposure to cold and post- operative state • Low values : hepatic diseases, chronic illness, anemia, malnutrition, malignancy decreased amt of gonadotropic and adrenocorticotropic hormones

7. Functions • Testosterone is the most active • Testosterone > androsterone > dehydroepiandrosterone > epiandrosterone • Promotes growth and function of the male accessory sex organs, viz prostate gland, seminal vesicles, Cowper’s glands and penis • Development of 20 sex characteristics viz texture of skin, distribution of hair, voice etc • Promotes protein syn in accessory organs • Increase the activity of glycolytic enzymes • Decrease the activity of alk.phosphatase, glutamic dehydrogenase & hepatic arginine synthetase

8. Functions • Increase the rate of synthesis of FAs • Increase the rate of production of fructose by the seminal vesicles • Increase the rate of synthesis of citrate • Increase respiration ( O2 consumption and CO2 production ) of the seminal vesicles and of the prostateincrease the tubular reabsorption of citrate, Na, K, Cl-, SO42-, PO43-

9. Hormones of Corpus luteum hormones • Pregnancy hormones / Gestogens • Progesterone is the most imp of this group • Secreted by corpus luteum part of ovary • Degraded to inactive pregnanediol • Main source : corpus luteum • Also found in placenta, pregnancy urine, and adrenal cortex

10. Biosynthesis • Acetate  • Corpus luteum , adrenal corted, testes and placenta • It is secreted a day or two earlier, or on the day of ovulation from the corpus luteum • Its secretion is stimulated by prolactin • It is bound in plasma to the corticosteroid-binding globulin (CBG) • The principal excretory product of progesterone is pregnanediol formed by the reduction of Progesterone

11. Functions • In conjunction with estrogenic hormones, it prepares the uterine mucosa for the reception of fertilized ovum • Maintains the conditions for its further growth • Exhibits antiovulatory property ( used as oral contraceptive) • In conjuction with estrogen, progesterone causes development of the alveolar system of the breast • Increases the BMR • Effects electrolyte and water metabolism

12. Relaxin • Another hormone from corpus luteum, placenta and uterus • Found in blood of pregnants • Chemically it is PP (mol.wt 90,000) • Mammary development in rats • Anti-diuretic effect in rats