Changes in cerebrospinal fluid and plasma vasopressin in the febrile sheep.

Plasma and cerebrospinal fluid (CSF) concentrations of vasopressin (AVP) were measured in conscious sheep during fever induced by iv endotoxin. Body temperature and blood pressure were also measured. AVP concentrations increased in both CSF and plasma although increases were not parallel. AVP concentrations in CSF were significantly correlated to increases in body temperature whereas plasma AVP concentrations were not. Neither CSF nor plasma AVP concentrations were correlated with changes in blood pressure. These data indicate that there may be independent regulation of AVP release into plasma and CSF compartments and supports the idea that AVP may have several physiological functions to perform during fever.