THE EFFECT OF VARIOUS CONDITIONS ON THE RESPIRATION OF RAT HEART MUSCLE IN VITRO

Abstract

Rat ven-tricle incubated 5-20 mins. at 37[degree] before slicing has a depressed respiration. At 5[degree] it is possible to incubate the heart for 30 mins. without depression of the subsequent respiration. Slices made from incubated hearts still oxidize succinic, lactic, and pyruvic acids. Fresh or incubated slices are unable to oxidize, acetate, alanine, glutamic acid, adenylic acid, fumaric acid, tyramine, glucose, Cori ester, Embden ester, or mannose. The simultaneous absence of K, Ca and Mg depresses the respiration of heart muscle slices irreversibly.