q._____________? - sarim

[ArchivalUser]

MBME 1 Q.


After taking an overdose of propranolol, a 35 year old woman develops sinus bradycardia and syncope, In order to stimulate the same second messenger system that is activated by beta adrenergic receptors, which of the following drugs will be most effective to increase her heart rate?

A. ADH (vasopressin)
B. Atrial natriuretic peptide
C. Clonidine
D. Glucagon
E. Phenylephrine

[ArchivalUser]

d?

[ArchivalUser]

Why is that ?

[ArchivalUser]

glucagon increasing HR.....???????

I know that Beta 2 and glucagon act via GS coupling

[ArchivalUser]

D - Glucagon. Glucagon is an antidote for beta-blocker overdose. It acts via the Gs second messenger system which is the same p/way used by beta receptors. Gs ---> +Adenyl cyclase ---> increase cAMP ---> incr protein kinase A --> increase contractility.

[ArchivalUser]

I meant ---> increase heart rate.

[ArchivalUser]

the likely mechanism of action is the increase of cAMP in the myocardium, in effect bypassing the β-adrenergic second messenger system.

Thanks chucke....sarim where do you find the questions??? Thanks

[ArchivalUser]

D...also through Gs