Male sex hormones

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

2. Male sex hormones
 Androgens or androgenic hormones
 Testosterone, androsterone, dehydroepiandr
osterone
 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, dehydroepiandroste
rone, 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-, SO4
2-, PO4
3-

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