Effect of Environmental Temperature on Reaction of Mice to Parathion, an Anticholinesterase Agent

Abstract

Mice were exposed to three environmental temperatures, 60°, 73° and 96°F, for 3 days before and after intraperitoneal injection with an anticholinesterase, parathion. The onset of deaths, rate of dying and rate of recovery were more rapid, the survival time of the fatal cases was shorter, and the mortality was higher at 96° than at 73°F. At 60°F, the onset of deaths was delayed, and the final but not the early mortality exceeded that at 73°F. Somewhat similar, though less significant, differences occurred with intravenous injections. Experiments with different pre- and postinjection temperatures showed that mortality varied directly with pre- and inversely with postinjection temperatures and latent period varied inversely with preinjection temperatures. For comparison, acetylcholine and neostigmine were injected intraperitoneally in mice at these three temperatures. The rate of dying and mortality were only slightly greater at 96° than at 73°F. At 60°F the onset of deaths was delayed, the animals died more slowly and the mortality was significantly lower than at 73°F. The results cannot be attributed to acceleration of chemical reactions with changes in body temperature but appear to be due to variations in rate of absorption and other factors.