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Androgens and Progestins

Androgens and Progestins. Dr. Alia Shatanawi March 10 th 2013. Estrogens and Progestins. Androgens. Testosterone. Estradiol Estrone Estriol Progesterone. Function of Gonadal Steroids. Govern the development, maturation and nutritional support germ cells

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Androgens and Progestins

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  1. Androgens and Progestins Dr. Alia Shatanawi March 10th 2013

  2. Estrogens and Progestins Androgens • Testosterone • Estradiol • Estrone • Estriol • Progesterone

  3. Function of Gonadal Steroids • Govern the development, maturation and nutritional support germ cells • Promote the capacity for reproduction • Control secondary sex characteristics • In Women Progestins, help maintain pregnancy • Pro-gestation : maintain pregnancy

  4. Δ-Isomerase 3-ß-hydroxysteroid dehydrogenase

  5. Hypothalamic-pituitary-gonadal axis Hypothalamus GnRH pulses Anterior pituitary LH FSH cAMP cholesterol tnsp. Estrogens Androgens ovary / testis

  6. Hypothalamic-Pituitary-Gonadal Axis • GnRH stimulates anterior pituitary gonadotropes to make LH and FSH • LH & FSH then stimulate gonads to produce sex steroids (testosterone in males; estradiol in females) and gametes • Sex steroids have negative feedback on both hypothalamus & pituitary (males & females) • Estradiol has positive feedback in females just prior to ovulation

  7. + Estrogen

  8. LH function • In females, an acute rise of LH called the LH surge triggers ovulation and development of the corpus luteum. • In males, where LH had also been called interstitial cell-stimulating hormone (ICSH), it stimulates Leydig cell production of testosterone

  9. FSH function • In both males and females, FSH stimulates the maturation of germ cells. • In males, FSH induces Sertoli cells to secrete inhibin and stimulates the formation of sertoli-sertoli tight junctions. • In females, FSH initiates follicular growth, specifically affecting granulosa cells.

  10. Paradoxes of Estrogens reproduction – contraception young to mature – older to younger carcinogenic? – chemotherapeutic Estrogen, “oistros” (drives mad or causes a frenzy)

  11. Sources of Estrogen • androgens estrogens • ovarian granulosa cells • “extraglandular aromatization” in adipose tissue • Sertoli / Leydig cells • brain regions • placenta aromatase

  12. Developmental Actions of Estrogens • Growth and development of female reproductive tract: • uterus • vagina • fallopian tubes • Enlargement of breasts • Female body contour • Pigmentation of breasts and genital region

  13. MENOPAUSE Complication Alleviation Genitourinary atrophy painful intercourse dysuria infections Restore epithelium H Stabilize heat-releasing mechanisms Vasomotor instability hot flashes R Osteoporosis fractures Prevent bone resorption T CV disease M.I. hypertension stroke Reduce risk ??? LDL/HDL protect endothelium antioxidant vasodilation reduce atherosclerosis

  14. PREPARATIONS & ADMINISTRATION Oral Ethinylestradiol Conjugated estrogens (DES) Diethylstilbestrol Transdermal Patches Injected Estradiol esters in oil Topical vaginal cremes vaginal rings

  15. Use of antiestrogen to treat infertility Arcuate nucleus GnRH pulses CLOMIPHENE Anterior pituitary feedback inhibition INCREASED GONADOTROPIN SECRETION LH FSH cAMP cholesterol tnsp. estrogens androgens ovary / testis

  16. CLOMIPHENE (Clomid) • Selective estrogen receptor modulator (SERM) • MOA: increases production of gonadotropins by inhibiting negative feedback on the hypothalamus • Induce ovulation in females Uses: • Infertility in polycystic ovary syndrome • ovarian hyperstimulation, in vitro fertilization

  17. PROGESTINS Maintain pregnancy HRT Oral contraceptives Menstrual problems suppress metalloproteinase activity Progesterone esters: MEDROXYPROGESTERONE ACETATE NORETHINDRONE NORGESTREL Antagonist: MIFEPRISTONE

  18. PROGESTERONE USES Supports pregnancy in IVF control persistent anovulatory bleeding prepare uterine lining in infertility therapy and to support early pregnancy preventing preterm birth in women at risk for preterm birth It is being investigated as potentially beneficial in treating multiple sclerosis

  19. ORAL CONTRACEPTIVES Arcuate nucleus GnRH pulses inhibit progestins Anterior pituitary inhibit estrogens thicken cervical mucus decrease decrease FSH LH Suppression of follicular development Suppression of ovulation

  20. Oral Contraceptives: EstrogensProgestins Ethinyl estradiol Norethindrone Mestranol Norgestrel (5 more) Formulations Combination Progestin-only 1) monophasic 2) biphasic 3) triphasic

  21. Potential Benefits of “The Pill” Better menstrual control dysmenorrhea dysfunctional bleeding Reduced incidence of sexually transmitted diseases cervical mucus Reduced incidence of uterine or ovarian cancer Reduced fibrocystic disease of the breast Reduced incidence of rheumatoid arthritis

  22. Oral Contraception • Combined oral contraception (COC) • Progestogen only pill (POP) • Emergency Hormonal Contraception (EHC)

  23. Contains oestrogen and progestogen Take one tablet daily for 21 days (28 for ED) followed by a 7 day pill free period Most effective preparation for general use With optimal use, > 99% effective Combined Oral Contraception

  24. Combined Oral Contraception • Monophasic • fixed amount of an oestrogen and a progestogen in each active tablet • Biphasic/Triphasic • varying amounts of the two hormones according to the stage of the cycle • ED (every day) • includes 7 days of placebo tablets

  25. Combined Oral Contraception How does it work?

  26. Oral Contraception • Combined oral contraception (COC) • Progestogen only pill (POP) • Emergency Hormonal Contraception (EHC)

  27. Progestogen only pill • Contains one active ingredient - progesterone • Taken continuously – no break • Offers an alternative when oestrogens are contraindicated • Efficacy dependent on the meticulousness of the user

  28. Oral Contraception • Combined oral contraception (COC) • Progestogen only pill (POP) • Emergency Hormonal Contraception (EHC)

  29. Emergency Hormonal Contraception • Levonelle 1500 (one step) • Contains high dose progesterone (levonorgesterel) • One 1500mcg tablet taken as soon as possible after unprotected intercourse (up to 72 hours after) • Preferably within 12 hours, no later than 72 hours

  30. When is EHC indicated? • Unprotected sexual intercourse • Reduced efficacy of other forms of contraception: • Torn, leaking condom • Missed pills • Late implant or injection • Detached contraceptive patch

  31. How does EHC work? • Dependent on point in the menstrual cycle • Either prevents or delays ovulation, prevents fertilisation or prevents implantation of the fertilised egg into the uterus. • Clinical opinion is that EHC is not an abortifacient

  32. Drug Interactions • The effectiveness of oral contraceptives will be reduced by interaction with drugs that are enzyme inducers • Broad spectrum antibiotics may reduce effectiveness of oral contraceptives

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