The role of arginine vasopressin in thermoregulation during fever.

Fever is common in postoperative neurosurgical patients. When fever is present, thermoregulatory responses regulate body temperature within a range that appears to have an upper limit. Endogenous substances, such as arginine vasopressin (AVP), modulate the thermoregulatory response during fever and are referred to as endogenous antipyretics. Endogenous antipyretics attenuate fever by influencing the thermoregulatory neurons in the preoptic region and anterior hypothalamus and in adjacent septal areas. Well known for its antidiuretic and vasopressive properties, AVP plays an important role in antipyresis via the ventral septal area of the limbic system. Evidence suggests that there may be a synergistic relationship between AVP receptors and cyclo-oxygenase enzyme during antipyresis, and the presence of AVP may enhance the efficacy of nonsteroidal antipyretic drugs. On the other hand, there is evidence that increased levels of AVP released during fever may play a role in febrile seizures. Although the antipyretic effect of AVP release during fever is beneficial, excessively high levels of AVP may be detrimental.