Hypothermic response following administration of 2-amino-4-pentenoic acid (allylglycine)

Intraperitoneal administration of allylglycine resulted in a hypothermic response in rats. At a dosage of 90 mg/kg, a significant decrease in temperature was noted at 4 and 8 hr after administration, but no significant difference was noted at 12 hr. The same dose administered intraperitoneally to decapitated rats did not result in a hypothermic response, and intraventricular administration resulted in a rapid onset of hypothermia after 1 hr. These findings are indicative of a central site of action for the allylgly-cine-induced hypothermia. Quantitative assay of hypothalamic monoamines (norepinephrine, serotonin, and dopamine) did not show any significant changes at 4, 8, and 12 hr postadministration when compared to controls. A significant decrease in hypothalamic γ-aminobutyric acid was noted at each of these time points when compared to controls. These data suggest an important role for γ-aminobutyric acid in mammalian thermoregulatory control.