Effect of Krebs cycle metabolites on frog heart.
All the Krebs metabolites except pyruvate, lactate, acetate and succinate reduced the force and rate of myocardial contractions and also decreased cardiac output in frog. Succinate on the contrary was found to augment the rate and force of heart. The cardiac stimulation produced by epinephrine was reduced by fumarate, malate, oxaloacetate and alpha-oxoglutarate, whereas transaconitate and citrate produced only a slight inhibition. Pyruvate, lactate, acetate and succinate did not alter cardiac response to epinephrine.
D000818:Animals; D001001:Anura; D002302:Cardiac Output / Q000187:drug effects; D004837:Epinephrine / Q000037:antagonists & inhibitors; D006321:Heart / Q000187:drug effects*; D006339:Heart Rate / Q000187:drug effects; D009200:Myocardial Contraction / Q000187:drug effects; D011898:Ranidae; D014233:Tricarboxylic Acids / Q000494:pharmacology*
D014233:Tricarboxylic Acids; D004837:Epinephrine