Document Detail


Chronic exercise training improves ACh-induced vasorelaxation in pulmonary arteries of pigs.
MedLine Citation:
PMID:  10658009     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
We hypothesized that exercise training would lead to enhanced endothelium-dependent vasodilation in porcine pulmonary arteries. Pulmonary artery rings (2- to 3-mm OD) were obtained from female Yucatan miniature swine with surgically induced coronary artery occlusion (ameroid occluder). Exercise training was performed for 16 wk, and vasomotor responses were studied by using standard isometric techniques. Contractile responses to 80 mM KCl, isosmotic KCl (10-100 mM), and norepinephrine (10(-8) to 10(-4) M) did not differ between sedentary (Sed) and exercise-trained (Ex) pigs. Relaxation was assessed to endothelium-dependent and endothelium-independent vasodilators after norepinephrine contraction. Pulmonary arteries of Ex pigs exhibited greater maximal relaxation to ACh (61.9 +/- 3.5%) than did those of Sed pigs (52.3 +/- 3.9%; P < 0.05). Endothelium-independent relaxation to sodium nitroprusside did not differ. Inhibition of nitric oxide synthase significantly decreased acetylcholine-induced relaxation, with greater inhibition in arteries from Ex pigs (P < 0.05). Inhibition of cyclooxygenase enhanced relaxation to acetylcholine in arteries from Sed pigs. We conclude that exercise training enhances endothelium-dependent (ACh-mediated) vasorelaxation in pulmonary arteries by mechanisms of increased reliance on nitric oxide and reduced production of a prostanoid constrictor.
Authors:
L R Johnson; J L Parker; M H Laughlin
Related Documents :
10662899 - Exercise training enhances relaxation of the isolated guinea-pig saphenous artery in re...
10409179 - Alpha-adrenergic vasoconstriction in active skeletal muscles during dynamic exercise.
7896599 - Forearm compression during exercise increases sympathetic nerve traffic.
18001359 - Brachial arterial dynamics during staged lower extremity exercise: utility and comparis...
10413069 - Influence of fr 167653, an inhibitor of tnf-alpha and il-1, on the cardiovascular respo...
19680049 - Effects of exercise on intraocular pressure and ocular blood flow: a review.
19594929 - Acute effects of a thermogenic nutritional supplement on cycling time to exhaustion and...
8904569 - Effects of n2o narcosis on breathing and effort sensations during exercise and inspirat...
3883079 - Exercise and hypertension.
Publication Detail:
Type:  In Vitro; Journal Article; Research Support, U.S. Gov't, P.H.S.    
Journal Detail:
Title:  Journal of applied physiology (Bethesda, Md. : 1985)     Volume:  88     ISSN:  8750-7587     ISO Abbreviation:  J. Appl. Physiol.     Publication Date:  2000 Feb 
Date Detail:
Created Date:  2000-03-03     Completed Date:  2000-03-03     Revised Date:  2007-11-14    
Medline Journal Info:
Nlm Unique ID:  8502536     Medline TA:  J Appl Physiol     Country:  UNITED STATES    
Other Details:
Languages:  eng     Pagination:  443-51     Citation Subset:  IM    
Affiliation:
Department of Veterinary Biomedical Sciences, University of Missouri, Columbia, Missouri 65211, USA. JohnsonLR@missouri.edu
Export Citation:
APA/MLA Format     Download EndNote     Download BibTex
MeSH Terms
Descriptor/Qualifier:
Acetylcholine / pharmacology*
Animals
Bradykinin / pharmacology
Dose-Response Relationship, Drug
Endothelium, Vascular / drug effects,  physiology
Enzyme Inhibitors / pharmacology
Female
Indomethacin / pharmacology
NG-Nitroarginine Methyl Ester / pharmacology
Nitroprusside / pharmacology
Norepinephrine / pharmacology
Physical Conditioning, Animal / physiology*
Potassium Chloride / pharmacology
Pulmonary Artery / drug effects*,  physiology
Swine
Swine, Miniature
Vasoconstriction / drug effects
Vasodilation / drug effects*
Grant Support
ID/Acronym/Agency:
HL-03856/HL/NHLBI NIH HHS; HL-36088/HL/NHLBI NIH HHS; HL-52490/HL/NHLBI NIH HHS
Chemical
Reg. No./Substance:
0/Enzyme Inhibitors; 15078-28-1/Nitroprusside; 50903-99-6/NG-Nitroarginine Methyl Ester; 51-41-2/Norepinephrine; 51-84-3/Acetylcholine; 53-86-1/Indomethacin; 58-82-2/Bradykinin; 7447-40-7/Potassium Chloride

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


Previous Document:  Microvascular and myocardial contractile responses to ischemia: influence of exercise training.
Next Document:  Measuring leg muscle and fat mass in humans: comparison of CT and dual-energy X-ray absorptiometry.