ATP-sensitive K+ channel blockade impairs O2 extraction during progressive ischemia in pig hindlimb.

Détails

ID Serval
serval:BIB_B9C8D2984FB5
Type
Article: article d'un périodique ou d'un magazine.
Collection
Publications
Titre
ATP-sensitive K+ channel blockade impairs O2 extraction during progressive ischemia in pig hindlimb.
Périodique
Journal of applied physiology
Auteur⸱e⸱s
Vallet B., Curtis S.E., Guery B., Mangalaboyi J., Menager P., Cain S.M., Chopin C., Dupuis B.A.
ISSN
8750-7587 (Print)
ISSN-L
0161-7567
Statut éditorial
Publié
Date de publication
12/1995
Peer-reviewed
Oui
Volume
79
Numéro
6
Pages
2035-2042
Langue
anglais
Notes
Publication types: Journal Article ; Research Support, Non-U.S. Gov't
Publication Status: ppublish
Résumé
Tissues maintain O2 consumption (VO2) when blood flow and O2 delivery (DO2) are decreased by better matching of blood flow to meet local cellular O2 demand, a process that increases extraction of available O2. This study tested the hypothesis that ATP-sensitive K+ channels play a significant role in the response of pig hindlimb to ischemia. We pump perfused the vascularly isolated but innervated right hindlimb of 14 anesthetized pigs with normoxic blood while measuring hindlimb DO2, VO2, perfusion pressure, and cytochrome aa3 redox state. In one-half of the pigs, the pump-perfused hindlimb was also infused with 10 micrograms.min-1.kg-1 of glibenclamide, a potent blocker of ATP-sensitive K+ channels. Control animals were infused with 5% glucose solution alone. Blood flow was then progressively reduced in both groups in 10 steps at 10-min intervals. Glibenclamide had no effect on any preischemic hindlimb or systemic measurements. Hindlimb VO2 and cytochrome aa3 redox state began to decrease at a significantly higher DO2 in glibenclamide-treated compared with control pigs. At this critical DO2, the O2 extraction ratio (VO2/DO2) was 53 +/- 4% in the glibenclamide group and 73 +/- 5% in the control group (P < 0.05). Hindlimb vascular resistance increased significantly with ischemia in the glibenclamide group but did not change in the control group. We conclude that ATP-sensitive K+ channels may be importantly involved in the vascular recruitment response that tried to meet tissue O2 needs as blood flow was progressively reduced in the pig hindlimb.
Mots-clé
Adenosine Triphosphate/pharmacology, Animals, Hemodynamics/physiology, Hindlimb/physiopathology, Ischemia/physiopathology, Oxygen/metabolism, Oxygen Consumption, Potassium Channels/drug effects, Swine, Vascular Resistance
Pubmed
Web of science
Création de la notice
29/04/2021 10:59
Dernière modification de la notice
17/07/2023 12:51
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