Interactions of cryptosin with mammalian cardiac dihydropyridine-specific calcium channels.
Cryptosin -a new cardenolide was found to be a potent inhibitor of cardiac Na+ and K+ dependent Adenosinetri-phosphatase (7). In experiments with dog heart ex vivo, development of inotropic and toxic effect correlated with changes in the cardiac dihydropyridine-specific calcium channels as measured by the binding of 3[H]PN 200-110. A significant change in the PN 200-110 binding was observed when guinea pig and dog heart sarcolemmal membranes were pre-incubated with cryptosin in vitro. Binding analysis of 3[H]PN 200-110 (Isradipine) - -a 1,4-dihydropyridine analog with very specific calcium channel binding properties - in both in vitro and ex vivo studies were consistent and indicated a non-specific type of interaction of cryptosin with mammalian cardiac 1,4-dihydropyridine-specific calcium channels.
Rao
V R
VR
Department of Pharmacology, College of Pharmacy, Wayne State University, Detroit, MI 48202.
Banning
J W
JW
D000818:Animals; D001667:Binding, Competitive; D002121:Calcium Channel Blockers / Q000378:metabolism*; D015220:Calcium Channels / Q000187:drug effects*; D002301:Cardiac Glycosides / Q000494:pharmacology*; D002462:Cell Membrane / Q000378:metabolism; D004285:Dogs; D005260:Female; D006168:Guinea Pigs; D066298:In Vitro Techniques; D017275:Isradipine; D008297:Male; D009206:Myocardium / Q000378:metabolism*; D010069:Oxadiazoles / Q000378:metabolism; D011978:Receptors, Nicotinic / Q000187:drug effects*; D012508:Sarcolemma / Q000378:metabolism
D002121:Calcium Channel Blockers; D015220:Calcium Channels; D002301:Cardiac Glycosides; D010069:Oxadiazoles; D011978:Receptors, Nicotinic; C060095:cryptosin; D017275:Isradipine