Question

Briefly, explain the general concept of a steroid hormone’s “permissive action” on peptide/amine hormones.

Answer 1

1.Corticoids have some direct and some permissive actions. By permissive action is meant that while they do not themselves produce an effect, their presence facilitates other hormones to exert that action, e.g. they do not have any eftect on BP but the pressor action of Adrenaline -Amino acid derivatibes is markedly blunted in their absence and increased several times in their presence because of expression of vascular adrenergic receptor .

2.The action of glucocorticoids on fat metabolism is primarily permissive in nature. They promote lipolysis due to glucagon, growth hormone, Adr and thyroxine. cAMP ( Cyclic adenosine monophosphate ) induced breakdown of triglycerides is enhanced.

3.They play a permissive role for the pressor action of Adrenaline and angiotensin,by increased expression of vascular adrenergic and Angiotensin receptor 1 as well as a permissive role in the development of hypertension. Hence Corticosteroids should be used cautiously in hypertensives.