Steroid Hormones

Steroid Hormones - Dr. P. Saranraj, Assistant Professor, Department of Microbiology, Sacred Heart College (Autonomous), Tirupattur, Vellore District, Tamil Nadu, India.

1. STEROID HORMONES Dr . P . Saranraj M.Sc., M.Phil. , Ph.D., NET Assistant Professor Department of Microbiology Sacred Heart College (Autonomous) Tirupattur, Vellore District. Mobile: [phone] E.mail: [email protected]

2. STEROID HORMONES A steroid hormone is a Steroid  that acts as a  hormone . Steroid hormones are the crucial substances for the proper functioning of body. Steroid hormones are produced in the adrenal cortex , testis , ovary and some peripheral tissues . All steroid hormones are derived from cholesterol and differ only in the ring structure and side chains attached to it. Enzymes which produce steroid hormones from cholesterol are located in Mitochondria and Smooth Endoplasmic Reticulum. All steroid hormones are Lipid soluble and Water insoluble . It is permeable to membranes so they are not stores in cells.

3. Steroid hormones are non-polar and can thus diffuse across lipid membranes . They leave cells shortly after synthesis.

4. TYPES OF STEROID HORMONES Glucocorticoids - originate in the adrenal cortex and affect mainly metabolism by ( i ) decreasing inflammation and (ii) Increasing resistance to stress . ( Eg .) Cortisol , Corticosterone , 11 – dehydro corticosterone & Cortisone Mineralocorticoids – originate in adrenal cortex and maintain salt and water balance. ( Eg .) Aldosterone Androgens - Androgens originate in the adrenal cortex and gonads and primarily affect maturation and function of secondary sex organs (male sexual determination). ( Eg .) Testosterone

5. 4) Estrogens - originate in the adrenal cortex and gonads and primarily affect maturation and function of secondary sex organs (female sexual determination). ( Eg .) Estradiol and Estrone 5) Progestogens (also known a progestins ) - Progestins originate from both ovaries and placenta, and mediate menstrual cycle and maintain pregnancy. ( Eg .) Pregnenolone and Progesterone

6. Aldosterone

7. Testosterone

8. Estradiol

9. Estrone

10. Pregnenolone

11. Progesterone

12. BIOSYNTHESIS OF STEROID HORMONES

13. FUNCTIONS OF STEROID HORMONES Steroid hormones plays a major role in Carbohydrate regulation Mineral balance Reproductive functions Inflammatory response Stress response Bone metabolism Cardiovascular fitness Activates DNA for Protein synthesis