Hormone mechanism of action

M.Prasad Naidu

MSc Medical Biochemistry,

Ph.D.Research Scholar

Classification based on mechanism of action

• Group 1 : bind to intracellular receptors.

eg; Androgens ,

calcitriol,

estrogens ,

glucocorticoids

progestrins

thyroid hormones

• Group II: Bind to cell surface receptors .

A. Second messenger cAMP

ACTH, ADH, hCG, CRH,FSH, LH, PTH.

B. cGMP as second messenger.

ANF (atrial natriuretic factor)

Nitric oxide (NO).

• C. Calcium / phosphatidyl inositols as second messenger

GnRH, TRH, PDGF, Substance P.

• D. Second messenger is a Kinase /phosphatase cascade

Insulin, GH, prolactin , insulin like growth factors(IGF-1,IGF-2).