🔴 Mechanism of Action 🔴

🔺 Corticosteroids :-

Corticosteroids secreted from Cortex of Adrenal gland...

Adrenal cortex has 3 regions..

a. Outer region Zona glomerulosa.... Secretes Mineralocorticods. ( Aldosterone)

b. Middle region Zona fasciculata..... Secretes Glucocorticoids. ( Hydrocortisone)

C. Inner region Zona reticularis ... Secretes Andrigens (dihydroepiandrosterone)

🔴 Mechanism of Action 🔴

🔺 Mineralocorticoids:-

Principle mineralocorticoid is Aldosterone... Action is enhancement of SODIUM reabsorption from distal convoluted tubules in kidney.

This corticosteroid also increases the in POTASSIUM and HYDROGEN ( proton) excretion.

The action of aldosterone is exerted by gene mediated increased transcription of m-RNA in renal tubule cells which directs synthesis of proteins (aldosterone induced proteins --- AIPs). These proteins acts on mitochondria to generate energy (ATP) and also synthesize the beta subunit of amiloride sensitive SODIUM channel.

So, Na* K* ATPase pump located on tubular basolateral membrane responsible for generating gradients for movement if cations in these cells is the major AIP.

In addition, aldosterone rapidly induces phosphorylation and activation of amiloride sensitive sodium channel.

🔴ADRS🔴
✔️MINERALOCORTICOIDS
▶️Sodium and water retension
▶️Edema
▶️Hypokalaemic alkalosis
▶️Progressively rise bp

✔️GLUCOCORTICOIDS
▶️Cushing habitus
▶️Fragile skin
▶️Hypoglycemia
▶️Peptic ulcer
▶️Osteoporosis

🔴 Mechanism of Action 🔴

🔺 Glucocorticoid :-

Corticosteroids penetrate cells and bind to cytoplasmic receptor protein.... Structural changes in steroidal receptor.... Form complex.... Enter or move into nucleus..... Bind with glucocorticoid responsive elements(GRE) on the chromatin ......promoting transcription of m-RNA..... Regulation protein synthesis ... Once appropriate proteins are synthesized... Effect persist .... Overall effect is catabolic.

🔺Glucocorticoid Actions :-

1.Carbohydrate metabolism
2.Protein metabolism
3.Fat metabolism
4.Calcium metabolism
5.Water excretion

6.CVS ... Restrict capillary permeability, maintain tone of arterioles and myocardial contractility.

7.Skeletal muscle weakness in hypocorticism as well as hypercorticism.

8.Stomach...secretion of Gastric acid and pepsin is increased.... May aggravate peptic ulcer.

9.Foetal lungs... Promote structural and functional maturation of fortal lungs near term. They stimulate production of pulmonary surfactants which are essential for inflation of foetal lungs at birth and air breathing.

10.Lymphoid tissue and blood cells.... T cells and B cells are more sensitive for destruction.
Glucocorticoids increase number of RBCs, platelets and neutrophils in circulation.

11. Inflammatory response

12.Immunological and allergic responses.

🔺Adverse reactions :-
▶️Cushing habitus
▶️Fragile skin
▶️Hypoglycemia
▶️Peptic ulcer
▶️Osteoporosis