NSC23766 [(N6-[2-[[4-(diethylamino)-1-methylbutyl]amino]-6-methyl-4-pyrimidinyl]-2-methyl-4,6-quinolinediamine trihydrochloride] is a widely used inhibitor of Rac1 activation. It is noteworthy that NSC23766 also created a rightward shift of the positive inotropic response curve caused by the cholinergic agonist, carbachol. In contrast, an adenosine A1 receptor-induced positive inotropic response in neonatal rat hearts was not changed by NSC23766. To investigate its specificity toward the different mAChR types, the carbachol-induced elevation in intracellular Ca2+ concentrations in HEK-293 cells expressing M1, M2 or M3 mAChRs was investigated. NSC23766 caused a concentration-dependent rightward shift of the carbachol concentration response curves at all mAChRs. Thus, NSC23766 is not only an inhibitor of Rac1 activation but also is a competitive antagonist at mAChRs within the same concentration range.
See article at J Pharmacol Exp Ther 2013, 347:69–79.
- Copyright © 2013 by The American Society for Pharmacology and Experimental Therapeutics