Male Sex Hormones

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ANDROGENS

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

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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

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Biosynthesis

• Cholesterol
• Testis, adrenal gland ovary
• Production release stimulated by ICSH
• Acetate ? Cholesterol ? pregnolone ? progesterone
  ? testosterone

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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

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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, dehydroepiandroster
  one, epiandrosterone.
• The amt of 17-KS increases with age and in
  pregnancy

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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

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Functions

• Testosterone is the most active
• Testosterone gt androsterone gt dehydroepiandrostero
  ne gt epiandrosterone
• Promotes growth and function of the male
  accessory sex organs, viz prostate gland, seminal
  vesicles, Cowpers 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

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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-

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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

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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-bindin
  g globulin (CBG)
• The principal excretory product of progesterone
  is pregnanediol formed by the reduction of
  Progesterone

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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

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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