The effects of perfusion of lateral ventricle with CaCl2 on the febrile response and cAMP content in plasma and cerebrospinal fluid during LP-induced fever.

Artificial cerebrospinal fluid (c.s.f.) containing 40 mmol/L excess calcium was perfused through the lateral ventricles of New Zealand white rabbits in order to reduce the Na+/Ca++ ratio in the brain and the effects on both the febrile response and adenosine cyclic monophosphate (cAMP) concentration in plasma and c.s.f. during leucocytic pyrogen (LP)-induced fever were observed. The results showed that cAMP concentration in c.s.f. increased significantly during LP-induced fever while the cAMP level in Plasma remained unchanged, and the perfusion of artificial c.s.f. containing 40 mmol/L excess calcium can significantly inhibit not only the febrile response but also the increase in c.s.f. cAMP level, while there appears no effect on plasma cAMP concentration, thus demonstrating that the increase of Na+/Ca++ ratio causing the increase of cAMP content in the brain may be an essential link in the pathogenesis of LP-induced fever.