Glycogenolysis is mediated by:

Ans: b (Alpha 1 + beta 2 receptors) Ref: Katzung, 10th ed, p. 130Glycogenolysis is mainly mediated by beta 2 receptors in the liver, but role of alpha 1 receptors have been mentioned in Katzung.Relative selectivity of adrenoceptor agonists. Relative Receptor AffinitiesAlpha agonists Phenylephrine, methoxaminea, > a 2 >>>>> bClonidine, methylnorepinephrinea 2> a1 >>>>> bMixed alpha and beta agonists Norepinephrinea1= a 2; b,>> b 2Epinephrinea1= a 2; b,= b 2Beta agonists Dobutamine b1 > b 2>>>> aIsoproterenol b1 = b 2>>>> aTerbutaline MetaproterenolAlbuterolRitodrine}b 2 >> b1>>>> aDopamine agonists Dopamine D1 =D2 >> b >> aFenoldopam D1 >> D2