[Effect of caffeine on chronotropic correlations in the myocardium of the rat and guinea pig].
Force-frequency relations in the isolated papillary muscles of rats and guinea-pigs were compared using isometric force measurement technique. Stimulation frequency varied between 0.33 and 4 Hz. Under normal conditions the rat papillary muscle exhibits a negative force-frequency dependence which differs from ventricular preparations in many other mammals. Caffeine (10 mmol/l) introduced into the bath solution abolishes a negative force-frequency dependence in the papillary muscle of rat. During incubation of the rat ventricular preparations in the caffeine-containing solution the force-frequency relations measured on these muscles display the same behaviour as in guinea pig preparations. Caffeine has induced no changes in the force-frequency relations of guinea-pig ventricular preparations. A conclusion is made that caffeine-sensitive intracellular calcium stores participate in species-determined differences in force-frequency relations of the ventricular muscles.
Shevchuk
V G
VG
Shmygol
A V
AV
Verkhratski?
A N
AN
Karvatski?
I N
IN
D000818:Animals; D002110:Caffeine / Q000494:pharmacology*; D006168:Guinea Pigs; D066298:In Vitro Techniques; D009200:Myocardial Contraction / Q000187:drug effects*; D010210:Papillary Muscles / Q000187:drug effects*; D051381:Rats; D013268:Stimulation, Chemical
D002110:Caffeine
Vliianie kofeina na khronoinotropnye vzaimootnosheniia v miokarde krysy i morskoĭ svinki.