Dose- and time-dependent effects of histamine on hypothalamic levels of interleukin-1β in rats

Some recent studies give support to the potential interaction between histamine (HA) and interleukin-1 (IL-1) in the central nervous system (CNS). At the peripheral level, HA acts as an immune modulator, but little is known on the neuroimmune role of this biogenic amine in the CNS. In the present study we have investigated the effects of HA, mepyramine, famotidine, thioperamide, and L-histidine on hypothalamic IL-1β. HA induced a time- and dose-dependent decrease in the concentration of IL-1β. The maximum effect was obtained 30 minutes after injection. The HA-induced IL-1β response in the hypothalamus was not inhibited by either mepyramine, famotidine or thioperamide. In addition, L-histidine exerted the same effect as HA. The interaction between HA and IL-1β in the CNS might be linked to neuroendocrine regulation as well as to neurotrophic activity and neuroimmune function.