Document Detail

Naloxone does not affect muscle blood flow during low intensity exercise in rats.
MedLine Citation:
PMID:  2927299     Owner:  NLM     Status:  MEDLINE    
The purpose of this study was to determine whether endogenous opioids are involved in the control of skeletal muscle blood flow during locomotory exercise in rats. The radiolabeled miscrosphere technique was used to measure total and regional muscle blood flow. We first determined whether methionine enkephalin (1,000 I.V.) would produce vasodilation in muscle vascular beds. We found that methionine enkephalin produced a 36 mm Hg (range of 20-50 mm Hg) drop in mean arterial pressure (Pa), which was associated with decreases in calculated skeletal muscle vascular resistance in anesthetized rats, and that these effects on arterial pressure and skeletal muscle vascular resistance were blocked by the infusion of naloxone (10 Measurements were then made at 5 min of treadmill exercise at 15 m.min-1 (0 degree incline) and following exercise in both saline-treated (controls) and naloxone (10 conscious rats. There were no differences between the heart rates, blood pressures, or total muscle blood flows of the two groups. There were also no significant differences between the blood flows to 32 hind limb muscle samples composed of various muscle fiber types. Since naloxone blockade did not affect total or regional muscle blood flow during low intensity exercise, it appears that the endogenous opioids are not required for the normal exercise hyperemia of skeletal muscles.
S J Mohrman; D F Peterson; M H Laughlin
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Publication Detail:
Type:  Journal Article; Research Support, U.S. Gov't, P.H.S.    
Journal Detail:
Title:  Medicine and science in sports and exercise     Volume:  21     ISSN:  0195-9131     ISO Abbreviation:  Med Sci Sports Exerc     Publication Date:  1989 Feb 
Date Detail:
Created Date:  1989-05-11     Completed Date:  1989-05-11     Revised Date:  2008-11-21    
Medline Journal Info:
Nlm Unique ID:  8005433     Medline TA:  Med Sci Sports Exerc     Country:  UNITED STATES    
Other Details:
Languages:  eng     Pagination:  34-9     Citation Subset:  IM; S    
Department of Veterinary Biomedical Sciences, University of Missouri, Columbia 65211.
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MeSH Terms
Endorphins / physiology*
Enkephalin, Methionine / pharmacology
Motor Activity
Muscles / blood supply*
Naloxone / pharmacology*
Physical Exertion*
Rats, Inbred Strains
Grant Support
Reg. No./Substance:
0/Endorphins; 465-65-6/Naloxone; 58569-55-4/Enkephalin, Methionine

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine

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