Studies on hypothermic mechanisms of endogenous cryogen(EC) / 中国病理生理杂志

ABSTRACT

Intracerebroventricular administration of purified EC induced a fall in rectal temperature of rabbits with an increase in ear skin temperature. Only 1/80th the amout of purified EC injected i. v. produced a comparable fall in rectal temperature when injected into the lateral ventricle of rabbits. ICV administration of purified EC resulted in a more rapid fall in rectal temperature than i. v. administration. This evidence strongly supports the hypothesis that EC has a primary site of action in the central nervous system.After intravenous administration of purified EC, with a fall in rectal temperature there was a significant decrease in levels of cyclic AMP in the cerebrospinal fluid of rabbits, but no change was found in levels of cyclic GMP in the cerebrospinal fluid. These data suggest that EC might induce hypothermia in rabbits by lowering levels of cyclic AMP in the brain and that cyclic GMP might not be involved in hypothermia caused by EC.