[The effect of obzidan, finoptin and Ca2+ on the cAMP level during contraction-relaxation of isolated heart of guinea pigs activated with isadrin].
The beta-adrenoceptor blockade, slow inward calcium current blockade and calcium concentration decrease in perfusion solution were studied for their effect on cAMP oscillations during cardiac cycle in the isadrin-activated isolated heart of guinea pig. Isadrin activation (3 X 10(-8) M) of beta-adrenoceptors caused an increase of the cAMP concentration by 50% during the contraction. All the actions decreased an average level of cyclonucleotide in the myocardium as compared with isadrin and what is more, obsidan (10(-6) M) removed the cAMP oscillations almost completely, the hypocalcium solution (0.15 mM Ca2+) decreased their amplitude and duration, finoptin (3 X 10(-8) M) qualitatively changed the oscillation profile. The results obtained make it possible to suggest, that a change in the concentration of ionized calcium in myoplasma is one of the reasons inducing changes in the cAMP during the cardiac cycle.
Laptev
B I
BI
Bardamova
I B
IB
Prokop'eva
V D
VD
Afanas'ev
S A
SA
Kenikh
N I
NI
Travkov
Iu A
IuA
D000818:Animals; D002118:Calcium / Q000494:pharmacology*; D000242:Cyclic AMP / Q000378:metabolism*; D005260:Female; D006168:Guinea Pigs; D066298:In Vitro Techniques; D007545:Isoproterenol / Q000494:pharmacology; D008297:Male; D009200:Myocardial Contraction / Q000187:drug effects*; D009206:Myocardium / Q000378:metabolism; D011433:Propranolol / Q000494:pharmacology*; D014700:Verapamil / Q000494:pharmacology*
D011433:Propranolol; D014700:Verapamil; D000242:Cyclic AMP; D007545:Isoproterenol; D002118:Calcium
Deĭstvie obzidana, finoptina i Ca2+ na soderzhanie cAMP v protsesse sokrashcheniia-rasslableniia izolirovannogo serdtsa morskoĭ svinki, aktivirovannogo izadrinom.