Androgens

A compact slide on Androgens, the male sex hormones.

1. ANDROGENS Anirban Kumar Bora Assistant Professor Gitanjali College of Pharmacy

2. INTRODUCTION Androgen actually means male sex hormones. Testosterone is the main androgen in men. It is mainly synthesized from Leydig cells or interstitial cells of the testes under the influence of ICSH (Interstitial Cell Stimulating Hormone) of anterior pituitary.

3. SYNTHESIS Large Amount: Leydig cells (Testes) Small Amount: Thecal cells (Ovaries) Adrenal glands

4. Androgens bind to specific nuclear receptor in a target cell. MECHANISM OF ACTION Androgen Cytoplasmic androgen receptor (AR) Testosterone receptor complex + DNA Androgen response element of target gene DNA transcription Protein synthesis

5. Masculinizing effect: Development of male secondary sexual characteristics Maturation of reproductive organs Anabolic effect: Promotes protein synthesis Increase muscle mass EFFECTS

6. Females: Acne Hirsutism Menstrual irregularities Males: Impotence Decreased spermatogenesis Children: Abnormal sexual maturation Growth disturbance ADVERSE EFFECTS

7. Natural Androgens Testosterone 5 α- Dihydrotestosterone (DHT) Androstenedione Dehydroepiandrosterone CLASSIFICATION Androgens

8. 2. Synthetic Androgens Methyltestosterone Fluoxymesterone 3. Anabolic steroids: Nandrolone decanoate (i.m.) Oxandrolone (p.o.) Stanozolol (p.o.) Ethylestrenol (p.o.) CLASSIFICATION

9. Antiandrogens CLASSIFICATION 1. Physiological antagonist: Oestrogen 2. Testosterone synthesis inhibitors: Ketoconazole Spironolactone

10. CLASSIFICATION 3. Androgen receptor antagonist: Flutamide Bicalutamide Cyproterone Spironolactone 4. 5α- reductase inhibitors: Finasteride Dutasteride

11. Oestrogens decrease androgen levels by inhibiting gonadotropin secretion. Ketoconazole (antifungal) inhibits adrenal and gonadal steroid synthesis. Spironolactone , an aldosterone antagonist, inhibits testosterone synthesis, also competitively blocks androgen receptors. Androgen receptor antagonists block action of androgens on the target cell. Finasteride and Dutasteride block the enzyme 5 α- reductase needed to convert to dihydrotestosterone (DHT) from testosterone. MOA of ANTIANDROGENS

12. Testosterone Levels: Male : 300- 1000 ng/dL Female : 15- 75 ng/dL Dihydrotestosterone: In most target cells, 4-5 double bond is reduced, converts testosterone [ abundant in muscle and liver] to dihydrotestosterone (DHT) [e.g. prostrate, seminal vesicles, skin etc]. ANNEX

13. THANK YOU