The decompensatory phase of acute hypovolaemia in rabbits involves a central delta 1-opioid receptor

Eur J Pharmacol. 1994 Jan 24;252(1):113-6. doi: 10.1016/0014-2999(94)90582-7.

Abstract

Graded caval occlusion in conscious rabbits caused a biphasic response. Phase I was characterized by a fall in conductance so that arterial pressure was maintained. When cardiac output had fallen to 69 +/- 2% of its baseline level, phase II supervened. During phase II, conductance rose abruptly and arterial pressure fell to a life-threatening level (< 40 mmHg). Centrally administered delta-opioid receptor antagonists prevented the occurrence of phase II. The relative order of potency was 7-benzylidene-naltrexone (BNTX, delta 1-selective) > N,N-diallyl-Tyr-Aib-Phe-Leu-OH (ICI 174,864) > naltrindole (delta 2-selective). It is concluded that a central delta 1-opioid receptor is involved in the onset of the second decompensatory phase of the haemodynamic response to haemorrhage.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Benzylidene Compounds / pharmacology
  • Blood Pressure / drug effects
  • Blood Pressure / physiology
  • Cardiac Output / drug effects
  • Cardiac Output / physiology
  • Enkephalin, Leucine / analogs & derivatives
  • Enkephalin, Leucine / pharmacology
  • Hemodynamics / drug effects*
  • Hemorrhage / physiopathology
  • Naltrexone / analogs & derivatives
  • Naltrexone / pharmacology
  • Narcotic Antagonists / pharmacology*
  • Rabbits
  • Receptors, Opioid, delta / antagonists & inhibitors
  • Receptors, Opioid, delta / physiology*
  • Shock / physiopathology*

Substances

  • Benzylidene Compounds
  • Narcotic Antagonists
  • Receptors, Opioid, delta
  • 7-benzylidenenaltrexone
  • Enkephalin, Leucine
  • Naltrexone
  • N,N-diallyl-tyrosyl-alpha-aminoisobutyric acid-phenylalanyl-leucine
  • naltrindole