Suppression of guinea pig ileum induced contractility by plasma albumin of hibernators

Pharmacology Biochemistry and Behavior
By: , and 

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Abstract

Previous studies suggest that hibernation may be regulated by internal opioids and that the putative “hibernation induction trigger” (HIT) may itself be an opioid. This study examined the effect of plasma albumin (known to bind HIT) on induced contractility of the guinea pig ileum muscle strip. Morphine (400 nM) depressed contractility and 100 nM naloxone restored it. Ten milligrams of lyophilized plasma albumin fractions from hibernating ground squirrels, woodchucks, black bears, and polar bears produced similar inhibition, with partial reversal by naloxone. Five hundredths mg of d-Ala2-d-Leu5-enkephalin (DADLE) also inhibited contractility and naloxone reversed it. Conclusions are that hibernating individuals of these species contain an HIT substance that is opioid in nature and summer animals do not; an endogenous opioid similar to leu-enkephalin may be the HIT compound or give rise to it.

Additional publication details

Publication type Article
Publication Subtype Journal Article
Title Suppression of guinea pig ileum induced contractility by plasma albumin of hibernators
Series title Pharmacology Biochemistry and Behavior
DOI 10.1016/0091-3057(92)90658-3
Volume 43
Issue 1
Year Published 1992
Language English
Publisher Elsevier
Contributing office(s) Alaska Science Center
Description 5 p.
First page 199
Last page 203