Astrocytes rather than neurones mediate interleukin-1 beta dependent nitric oxide and superoxide radical release in primary hypothalamic rat cell cultures

The cellular sources of nitric oxide in the hypothalamus are thought to be 'NOergic' neurones. Using free radical electrochemical sensors we investiga ted nitric oxide and superoxide radical release in primary hypothalamic cel l cultures. We present evidence that under interteukin-1 beta (IL-1 beta) s timulation hypothalamic astrocytes rather than neurones release nitric oxid e. Under L-arginine deprivation and IL-1 beta stimulation a concentration-d ependent release of superoxide was also observed, which was inhibited in th e presence of nitric oxide synthase inhibitor nitro-L-arginine-methyl-ester . These findings support the hypothesis that the balance between nitric oxi de and superoxide may be of vital importance in hypothalamic pathophysiolog y. (C) 1999 Elsevier Science Ireland Ltd. All rights reserved.