WASHINGTON, Jun 14 - Dr. Nancy J. Rothwell and her associates from the University of Manchester, UK reported in the June 8th Proceedings of the National Academy of Sciences (PNAS) that leptin induces production of the cytokine interleukin-1 (IL-1) in the brain during the course of the infectious process in rats and mice.
In talking to repoters she is quoted as having said,
Even in normal rats, apparently, leptin injected into either (1) the cerebral 3rd or 4th ventricules or (2) peripherally switched on IL-1, dose-dependently increasing core body temperature and appetite suppression. Blocking IL-1 inhibited these responses to leptin. Moreover, "Leptin failed to affect food intake or body temperature in obese Zucker rats, which possess a defective leptin receptor."