<prompt> Glycogenolysis is mediated by:Alpha 1 receptorAlpha lbeta2 receptorBeta 2 receptorAlpha 2 beta 1 receptor  <response>: 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 MetaproterenolAlbuterolRitodrineb 2 b1 aDopamine agonists Dopamine D1 D2 b aFenoldopam D1 D2 