Sex hormones

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• SEX HORMONES

M.PRASAD NAIDU Msc Medical Biochemistry, Ph.D
Research scholar.
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Introduction

• Steroid hormones
• Synthesized in mammals by the ovary, testis,
  A.cortex corpus luteum and placenta
• The activity of sex hormones controlled by the
  adenohypophyseal hormones.
• Bcos of this, the sex hormones are, some times
  referred to as 20 sex hormones of the
  adenohypophysis.
• 3 types are sex hormones are recognized.
• 1. the estrogens (female / ovarian / follicular
  hormones)
• 2. the androgens ( male / testicular hormones)
• 3. the gestogens ( corpus luteal hormones)

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introduction

• The sex hormones are concerned with sexual
  processes and the development of 20
  characteristics which differentiate males from
  females
• The adrenal cortical hormones perform a variety
  of important functions related to cell
  metabolism.
• Based on the no.of C atoms present in the
  molecule, the steroid hormones may be named as
  C18,C19 or C21 steroids.

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Ovarian hormones (C18 steroids)

• Structure-
• Mammalian ovary contains ovarian follicles and
  corpus lutea.
• Hormones produced mainly in the follicles are
  known as estrogens.
• Estrogens are derivatives of C18 hydro carbon,
  estrane.
• The imp estrogens are
• 1. ß-estradiol ( C18H24O2)
• 2. Estriol (C18H24O3)
• 3. Estrone (C18H22O2)

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estrogens

• Estrone is the 1st known member of the sex
  hormones.
• Isolated from the urine of pregnants.
• All these are characterized by the absence of a
  CH3 group at C10 and by the aromatic ring A,
  making the OH group phenolic in character.
• ?-estradiol is the most potent estrogens.
• Estrone is less potent and estriol is least
  active.
• Their relative potencies are 5051.
• Although ovary is the chief source of estrogens,
  they are in smaller amts also produced by the
  testis A.cortex.

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biosynthesis

• Estrogen production is highest when a woman is
  young slows down with ? age.
• Biosynthesis-
• In non-pregnant females, estrogen is mainly
  synthesized in the ovary.
• The estrogen(as well as androgen) transported by
  binding to a specific plasma protein called sex
  steroid binding protein.
• The amt of SBT increases in pregnancy or estrogen
  therapy which results in reduced androgenic
  action.
• Testosterone, an androgen is the precursor of
  estrogens.

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metabolism

• Most of the metabolic reactions of the estrogens
  take place in the liver
• Estradial - 17ß ? 2-OH-estradiol-17ß ?
  2-methoxyestradiol-17ß ?
  2-methoxyestrone
• Estrone ? 16a-hydroxyestrone
• ? ?
• 2-OHestrone Estriol
• Estriol is the principal estrogen found in the
  placenta and urine of pregnants.
• It is produced by hydroxylation of estrone at C16
  and reduction of keto group at C17

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Synthesis of estrogen

• Acetate? cholesterol ? pregnenolon? progesteron ?
  testosterone ? estrogen
• Regulation of Secretion of Estrogen-
• The secretion of estrogen is regulated by FSH
  released from anterior pituitary.
• The release of FSH is caused by the gonadotropic
  releasing hormone secreted from hypothalamus.

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functions

• Effects on uterus
• Effects on fallopian tubes
• Effects on vagina
• Effect on the breast
• Effects on 20 sexual characteristics
• Effects on bones
• Effects on protein fat metabolism
• Effects on electrolyte balance

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