ABDOMINAL VAGOTOMY ATTENUATES INTERLEUKIN-1-BETA-INDUCED NITRIC-OXIDERELEASE IN THE PARAVENTRICULAR NUCLEUS REGION IN CONSCIOUS RATS

Nitric oxide (NO) has recently been shown to modulate the hypothalamic -pituitary-adrenal axis response to interleukin-1 beta (IL-1 beta). We measured levels of nitrite (NO2-) and nitrate (NO3-) in the hypothala mic paraventricular nucleus (PVN) region using an in vivo brain microd ialysis technique in conscious rats. Intraperitoneally administered IL -1 beta produced a significant increase in both NO2- and NO3- levels i n the PVN region. We also examined the possible involvement of the abd ominal vagal afferent nerves in this effect. In abdominal-vagotomized rats, the increase was significantly attenuated compared to that in sh am-operated rats. Our results suggest that the abdominal vagal afferen t nerves are involved in intraperitoneally administered IL-1 beta-indu ced NO release in the PVN region. (C) 1998 Elsevier Science B.V.