Male Sex Hormones - PowerPoint PPT Presentation

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Male Sex Hormones

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Title: 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, 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, dehydroepiandroster
    one, 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 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

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-bindin
    g 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
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