Document Detail

Exercise increases the phenylephrine effects in isolated portal vein of trained rats.
MedLine Citation:
PMID:  19520188     Owner:  NLM     Status:  MEDLINE    
Physical exercise evokes an extensive circulatory redistribution. However, the influence of exercise upon the effects of sympathomimetic agonists in veins was not well studied. Thus, the present study aimed to determine whether a single bout of exercise modifies the effects of sympathomimetic agonists in veins and whether this exercise-induced modification may be altered by exercise training. The results have shown that the training did not change the responsiveness of the rat portal vein, but exposure of trained animals to a single bout of exercise enhanced the phenylephrine Rmax in these preparations. Such exercise-induced modifications of vascular response were territory-specific since similar modifications of response to phenylephrine were not observed in vena cava. Moreover, this exercise-induced augmentation of phenylephrine Rmax in the portal vein of trained rats was prevented by endothelium removal or in the presence of N(omega)-nitro-L-arginine methyl ester hydrochloride (L-NAME), indomethacin, BQ-123 or BQ-788. In conclusion, these data indicate that the training adapted the rat portal vein to respond vigorously to sympathetic stimuli even when the animal is exposed to this exercise. This increased response to sympathetic stimuli appears to involve an enhancement of the vasocontractile influence of endothelin that supplants the modulation exerted by nitric oxide (NO) and vasodilator prostanoids.
Agnaldo Bruno Chies; Patrícia de Souza Rossignoli
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Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't     Date:  2009-06-09
Journal Detail:
Title:  Vascular pharmacology     Volume:  51     ISSN:  1879-3649     ISO Abbreviation:  Vascul. Pharmacol.     Publication Date:    2009 Aug-Sep
Date Detail:
Created Date:  2009-08-11     Completed Date:  2009-10-30     Revised Date:  -    
Medline Journal Info:
Nlm Unique ID:  101130615     Medline TA:  Vascul Pharmacol     Country:  United States    
Other Details:
Languages:  eng     Pagination:  125-32     Citation Subset:  IM    
Laboratory of Pharmacology, Faculty of Medicine of Marília, Av. Monte Carmelo, 800, Fragata, 17 519-030, Marília, SP, Brazil.
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MeSH Terms
Analysis of Variance
Cyclooxygenase Inhibitors / pharmacology
Dose-Response Relationship, Drug
Endothelium, Vascular / physiology
Nitric Oxide Synthase / antagonists & inhibitors
Phenylephrine / pharmacology*
Physical Conditioning, Animal / physiology*
Physical Exertion / physiology*
Portal Vein / drug effects*,  physiology
Random Allocation
Rats, Wistar
Receptor, Endothelin A / antagonists & inhibitors
Receptor, Endothelin B / antagonists & inhibitors
Sympathomimetics / pharmacology*
Venae Cavae / drug effects
Reg. No./Substance:
0/Cyclooxygenase Inhibitors; 0/Receptor, Endothelin A; 0/Receptor, Endothelin B; 0/Sympathomimetics; 59-42-7/Phenylephrine; EC Oxide Synthase

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