Prostaglandin E2 mediates activation of hypothalamic histamine by interleukin-1beta in rats

Proc Soc Exp Biol Med. 1999 Feb;220(2):88-93. doi: 10.1046/j.1525-1373.1999.d01-14.x.

Abstract

The present study was designed to investigate the effects of peripheral interleukin-1beta (IL-1beta) on hypothalamic histamine (HA) systems. Intraperitoneal injection of IL-1beta increased the turnover rate of hypothalamic HA, which was assessed by accumulation of tele-methylhistamine after pargyline treatment. IL-1beta increased the activities of both histidine decarboxylase (HDC), an HA synthesizing enzyme, and HA-N-methyltransferase (HMT), an HA catabolizing enzyme. Pretreatment with indomethacin completely blocked the effects induced by IL-1beta on hypothalamic HA. Infusion of prostaglandin E2 (PGE2) into the third cerebroventricle increased the hypothalamic HA turnover rate, and simultaneously activated both HDC and HMT dose-dependently, but intravenous infusion of PGE2 had no effect on the dynamics of hypothalamic HA turnover. These results indicate that hypothalamic PGE2 activated by peripheral administration of IL-1beta, but not by peripheral PGE2, may enhance synthesis and release of hypothalamic HA by activation of HDC, and may facilitate degradation of extracellular histamine by activation of HMT.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Body Temperature Regulation / drug effects
  • Body Temperature Regulation / physiology
  • Dinoprostone / administration & dosage
  • Dinoprostone / pharmacology*
  • Enzyme Activation / drug effects
  • Histamine / metabolism*
  • Histamine N-Methyltransferase / metabolism
  • Histamine Release / drug effects
  • Histidine Decarboxylase / metabolism
  • Hypothalamus / drug effects*
  • Hypothalamus / physiology*
  • Indomethacin / pharmacology
  • Infusions, Intravenous
  • Injections, Intraperitoneal
  • Injections, Intraventricular
  • Interleukin-1 / administration & dosage
  • Interleukin-1 / pharmacology*
  • Male
  • Pargyline / pharmacology
  • Rats
  • Rats, Wistar

Substances

  • Interleukin-1
  • Histamine
  • Pargyline
  • Histamine N-Methyltransferase
  • Histidine Decarboxylase
  • Dinoprostone
  • Indomethacin