Caffeine contracture in frog cardiac muscle after exposure to high concentrations of calcium.
Caffeine induced contracture in frog auricular muscle at room temperature when the muscle was exposed to a Ca-rich solution. The initial transient tension lasted 10-30 sec, and it was inhibited by procaine. It was dependent on caffeine concentration and the time of exposure to a Ca-rich solution prior to caffeine attack, but was little dependent on Ca concentration during caffeine contracture.
D000818:Animals; D001001:Anura; D002110:Caffeine / Q000494:pharmacology*; D002118:Calcium / Q000494:pharmacology*; D066298:In Vitro Techniques; D009200:Myocardial Contraction / Q000187:drug effects*; D011343:Procaine / Q000494:pharmacology; D011892:Rana catesbeiana
D002110:Caffeine; D011343:Procaine; D002118:Calcium