Influence of GABA-acting drugs on morphine-induced hyperthermia in rats.

A major inhibitory neurotransmitter of the nervous system, GABA (gamma-aminobutyric acid), is involved in mammalian thermoregulation. The present study investigated the influence of GABAergic neurotransmission-enhancing drugs, in a model of morphine-induced hyperthermia in conscious rats. We used body temperature assays to examine the effects of GABA-acting drugs on morphine-induced hyperthermia. In rats, low doses of morphine injected i.p. produced significant hyperthermia in a body temperature assay that was significantly attenuated upon pretreatment with GABA-acting drugs. These results suggest the existence of opioidergic-GABAergic interactions in a complex process of thermoregulation.