Steroid Hormones - Dr. P. Saranraj, Assistant Professor, Department of Microbiology, Sacred Heart College (Autonomous), Tirupattur, Vellore District, Tamil Nadu, India.
1. Dr. P. Saranraj M.Sc., M.Phil., Ph.D., NET
Assistant Professor
Department of Microbiology
Sacred Heart College (Autonomous)
Tirupattur, Vellore District.
Mobile: 9994146964
E.mail: microsaranraj@gmail.com
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
1) 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
2) Mineralocorticoids – originate in adrenal cortex and
maintain salt and water balance. (Eg.) Aldosterone
3) 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
16. 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