Document Detail

Physical conditioning can modulate endothelium-dependent vasorelaxation in rabbits.
MedLine Citation:
PMID:  8499405     Owner:  NLM     Status:  MEDLINE    
To investigate whether exercise training can modulate endothelium-dependent vasorelaxation, male New Zealand White rabbits were divided into either control or training groups. The training animals were trained on a treadmill with a running speed of 0.88 km/hr on a 0 degree grade for 10-60 minutes/day, 5 days/week for 8 weeks. After exercise training, the resting heart rate was lowered (p < 0.05). At the end of the experiments, three vessel segments, i.e., the thoracic aortas, the pulmonary arteries, and the common carotid arteries, were isolated and precontracted with norepinephrine. Acetylcholine-stimulated endothelium-derived relaxing factor (EDRF) release was assessed by bioassay in the presence of indomethacin (10(-5) M). Basal release of EDRF was examined by the addition of hemoglobin. In addition, the relaxing responses of the thoracic aortas and pulmonary arteries to A23187, a calcium ionophore, and to sodium nitroprusside, a direct vasodilator of vascular smooth muscle, were compared between control and trained groups to further investigate possible underlying mechanisms. The results indicated that after exercise training 1) both the thoracic aorta and pulmonary artery, but not the carotid artery, became more sensitive to acetylcholine-induced vasorelaxation; 2) no significant differences in basal release of EDRF between control and trained rabbits were observed; and 3) there were no significant differences in the vascular responses to A23187 or sodium nitroprusside between the two groups. Our data suggest that exercise training may enhance endothelium-dependent vasodilation to acetylcholine via the stimulated EDRF release and that this elevated sensitivity to acetylcholine may not be caused by the alteration of the relaxing response in vascular smooth muscle.
H I Chen; H T Li
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Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't    
Journal Detail:
Title:  Arteriosclerosis and thrombosis : a journal of vascular biology / American Heart Association     Volume:  13     ISSN:  1049-8834     ISO Abbreviation:  Arterioscler. Thromb.     Publication Date:  1993 Jun 
Date Detail:
Created Date:  1993-07-01     Completed Date:  1993-07-01     Revised Date:  2006-11-15    
Medline Journal Info:
Nlm Unique ID:  9101388     Medline TA:  Arterioscler Thromb     Country:  UNITED STATES    
Other Details:
Languages:  eng     Pagination:  852-6     Citation Subset:  IM    
Department of Physiology, Medical College, National Cheng-Kung University, Tainan, Taiwan, Republic of China.
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MeSH Terms
Acetylcholine / pharmacology
Aorta, Thoracic / physiology
Calcimycin / pharmacology
Heart Rate / physiology
Nitric Oxide / metabolism*
Nitroprusside / pharmacology
Physical Conditioning, Animal*
Pulmonary Artery / physiology
Vasodilation / drug effects*
Reg. No./Substance:
10102-43-9/Nitric Oxide; 15078-28-1/Nitroprusside; 51-84-3/Acetylcholine; 52665-69-7/Calcimycin

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

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