Intensity of respiration and phospholipid metabolism in isolated rat brain tissue at different temperatures in the presence of KCN

The respiration rate and intensity of phospholipid metabolism of a rat brain tissue homogenate was studied during incubation at different temperatures (37, 32 and 27°C) in medium with and without cyanide (0.5 and 1 mM). Both these parameters are directly dependent on incubation temperature between 27 and 37°C. The presence of cyanide in the medium inhibits both processes but phospholipid metabolism more so than respiration. The results indicate that phospholipid metabolism during cyanide poisoning is affected both by the toxic action of the cyanide itself directly, and by temperature, the lowering of which potentiates the toxic action.