Female Reproductive Hormones Dr. Hazrat Bilal Malakandi DPT (IPM&R, KMU)

Two major hormones Estrogen: most important is estradiol Progestin: most important is progesterone

Estrogens Nature Sites of secretion In non-pregnant woman by Steroid Sites of secretion In non-pregnant woman by Ovaries: theca interna. Granulosa cells and corpus luteum Adrenal cortex In pregnant woman by Ovaries, adrenal cortex and placenta

Types of Estrogens Estrone (E1): small amount secreted by ovaries and mostly formed in peripheral tissues from androgens secreted by adrenal cortex and ovaries. Most imp. estrogen in pregnancy and postmenopausal women. Beta-estradiol (E2): mainly from ovaries and most important estrogen in non-pregnant females. Estriol (E3): oxidative product of estradiol and estrone in liver, most abundant Estetrol (E4): produced only during pregnancy

Degradation and excretion Plasma transport In loose combination with Plasma albumin Specific estrogen-binding globulins Degradation and excretion Active Beta estradiol and estrone are converted into inactive estriol in liver Estrogens are conjugated in liver to form glucoronides and sulfates Conjugates are excreted mainly into urine and about 1/5 in bile.

Action of Estrogen 1. On Reproductive Organs On vagina Inc. in size and wall musculature Simple cubiodal epithelium is converted into stratified epithelium which is more resistant to trauma and infections. Increase glycogen deposition pH becomes more acidic due to conversion of glycogen into lactic acid by bacteria Lactobacilli in the lower genital tract of women utilize glycogen in vaginal epithelial cells as an energy source and produce lactic acid. The resultant vaginal acidity is believed to provide protection against HIV infection.

On External Genetallia Clitoris and labia minora increase in size Increase fat deposition in mons pubis and labia majora On Cervix Slight enlargement Epithelium become stratified Increase alkaline secretions to neutralize the acidic pH of vagina.

On Uterus On Fallopian Tubes On Ovaries Cubiodal epithelium becomes columnar Uterine glands develop Increase size, vascularity and glycogen contents On Fallopian Tubes Proliferation of glandular tissue Increase no. and activity of ciliated epithelium On Ovaries Estrogen inhibits LH and FSH secretion by negative feedback mechanism  so decrease ovarian functions  used as oral contraceptive

2. On Secondary Sexual Characters On Breast Initiate growth of breast Causes development of stroma and duct system Causes fat deposition in breast Hair Distribution Axillary and pubic hairs grow partly due to estrogen and mainly due to adrenal androgens.

On Skin On Pelvis On Voice Causes skin to become smooth and soft Causes increase skin vascularity On Pelvis Broadens pelvis Pelvic outlet become broad and ovoid On Voice Larynx retains its prepubertal size and voice remains high pitched

3. Other Effects On Skeletal On Protein Metabolism On Fat Metabolism Causes increase ossteoblastic activity Causes early union of epiphysis with shaft On Protein Metabolism Slightly increase in total body protein On Fat Metabolism Increase fat synthesis Increase fat deposition in subcutaneous tissue, breast etc.

On H2O and Electrolyte Metabolism On Menstrual Cycle Causes increase Na+, Cl- and H20 retention On Menstrual Cycle Estrogen is responsible for the proliferative phase of menstrual cycle. On Blood Decrease blood cholesterol level Raises fibrinogen level

Progesterone Nature Sites of secretion Steroid In non-pregnant woman by Corpus luteum in later half of ovarian cycle Small amounts by adrenal cortex In pregnant woman by Corpus luteum Adrenal cortex Placenta (esp. after 4 months)

Degradation and excretion Types of Progestin Progesterone (more important) 17-alpha-hydroxyprogesterone Plasma Transport 2% is free circulating In loose combination with Plasma albumin – 80% Specific progesterone-binding globulins- 18 % Degradation and excretion Progesterone is degraded in liver into pregnandiol, which is excreted in urine.

Actions of Progesterone On Uterus Promotes secretary changes in uterine endometrium during secretary phase of menstrual cycle. Decrease frequency of uterine contraction On Fallopian Tubes Promotes secretary changes in mucosal lining, needed for nutrition of fertilized ovum Increase peristalsis from mouth of fallopian tube to uterus

On Breast On ovulation Promotes development of lobule and alveoli Causes alveolar cells to proliferate, enlarge and to become secretary Does not cause milk secretion On ovulation Inhibits ovulation by inhibiting release of LH & FSH. During pregnancy, ovulation is inhibited by luteal and placental progesterone

On H2O and Electrolyte Metabolism Causes slight retention of NA+, Cl- and H2O from renal tubules On Protein Metabolism Mobilizes protein during pregnancy to be used by fetus.