EFFECTS OF GAMMA-HYDROXYBUTYRIC ACID ON METABOLIC, RESPIRATORY AND VASOMOTOR ACTIVITIES AND BODY-TEMPERATURE IN RATS

Abstract

The effects of .gamma.-hydroxybutyric acid (GHBA) on metabolic, respiratory and vasomotor activities and body temperature were assessed in unanesthetized rats at 3 different ambient temperatures (Ta) of 8, 22 and 30.degree. C. I.p. administration of GHBA produced dose-dependent hypothermia in rats at both 8 and 22.degree. C Ta. At Ta = 8.degree. C the hypothermia was brought about solely by a decrease in metabolic heat production. At Ta = 22.degree. C the hypothermia was due to a decrease in metabolic heat production and an increase in cutaneous circulation (as indicated by changes in tail and foot skin temperatures). At Ta = 30.degree. C GHBA administration produced no changes in rectal temperature or other thermoregulatory parameters. Respiratory evaporative heat loss was not affected by GHBA application. GHBA-induced hypothermia was antagonized by haloperiodal (a selective blocker of dopamine receptors), but not by p-chlorophenylalanine (an inhibitor of serotonin synthesis). GHBA apparently elicits a central dopamine receptor activation via release of endogenous dopamine and leads to a hypothermia.