Antipyretic action of centrally administered arginine vasopressin but not oxytocin in the cat.

The antipyretic action of central arginine vasopressin (AVP) was investigated in mongrel cats. Control push-pull perfusions in the ventral septal area (VSA), with the carrier vehicle alone, did not affect the febrile response to Salmonella typhosa administered intracerebroventricularly. When AVP was perfused similarly, the fever was suppressed in a dose-related manner. The lower dose of AVP delayed the onset of fever, whereas the higher concentration of AVP suppressed consistently the fever throughout the period of administration. Another neurohypophyseal peptide, oxytocin, was ineffective in altering the febrile response at the dose tested. The regions of greatest sensitivity to the antipyretic action of AVP are located ventral to the septum, bounded by the diagonal bands of Broca, extending into the posterior septal nucleus. Sites at which AVP was ineffective in producing antipyresis were found more dorsal and lateral to these. Thus, AVP suppresses fever in the cat via an action in the VSA that is dose related, and site specific and peptide specific. These data provide further evidence that AVP may be involved in the central mechanisms which control core temperature.