ACTIVATION OF SYMPATHETIC OUTFLOW BY RECOMBINANT HUMAN INTERLEUKIN-1-BETA IN CONSCIOUS RATS

The present study was undertaken to determine the effects of interleuk in-1 beta (IL-1 beta) on renal sympathetic nerve activity (RSNA), arte rial blood pressure (AP), heart rate (HR), and body temperature in con scious rats. Either intravenous or intracerebroventricular administrat ion of IL-1 beta elicited increases in AP, KR, and RSNA accompanied by a rise in body temperature. The maximum changes in AP, KR, and RSNA o ccurred 10-15 min after intravenous injection of IL-1 beta (100 ng) an d 20-25 min after intracerebroventricular injection (5 ng). The respon ses induced by the intravenous and intracerebroventricular injections lasted for similar to 15-30 min and did not appear when the animals we re pretreated with the cyclooxygenase inhibitor indomethacin (10 mg/kg iv). Moreover, intracerebroventricular injection of prostaglandin E(2 ) (1 pg) produced responses similar to those induced by IL-1 but with shorter latency. Plasma norepinephrine and adrenocorticotropic hormone concentrations were increased after IL-1 beta injection. The results suggested that IL-1 beta augments cardiovascular and sympathetic outfl ow through the central action of prostaglandin E(2) in conscious rats.