Action of preoptic injections of beta-endorphin on temperature regulation in rabbits.

Journal Article (Journal Article)

Male New Zealand White rabbits, Oryctolagus cuniculus, were stereotaxically implanted with a guide tube above the preoptic/anterior hypothalamus area (PO/AH) for the injection of the opioid peptide, beta-endorphin (beta-E), naloxone, sodium salicylate, or physiological saline. PO/AH and ear temperature, oxygen consumption, and evaporative heat loss (EHL) were recorded in free-moving rabbits before and after injection of saline followed with beta-E, naloxone, or sodium salicylate at ambient temperatures (Ta) of 2-31 degrees C. A 5-micrograms injection of beta-E promoted a rapid reduction in ear temperature followed by a prolonged rise in PO/AH (body) temperature. Preinjection with an isovolumetric amount of the opiate antagonist, naloxone, inhibited the thermoregulatory effects of beta-E. The beta-E-induced rise in body temperature was directly correlated with Ta. beta-E had no effect on oxygen consumption at Ta's of 5 and 27 degrees C. When measured 30 min after injection, beta-E demonstrated a significant inhibition of EHL at Ta's of 27 and 31 but not 5 degrees C. The beta-E-induced rise in body temperature was not antagonized with preinjections of sodium salicylate in the PO/AH. These data indicate that beta-E promotes a regulated increase in body temperature. The mechanism of activation appears to be distinct from that of an infectious fever.

Full Text

Duke Authors

Cited Authors

  • Rezvani, AH; Gordon, CJ; Heath, JE

Published Date

  • July 1982

Published In

Volume / Issue

  • 243 / 1

Start / End Page

  • R104 - R111

PubMed ID

  • 6283919

International Standard Serial Number (ISSN)

  • 0002-9513

Digital Object Identifier (DOI)

  • 10.1152/ajpregu.1982.243.1.R104


  • eng

Conference Location

  • United States