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

Details

Serval ID
serval:BIB_B9C8D2984FB5
Type
Article: article from journal or magazin.
Collection
Publications
Title
ATP-sensitive K+ channel blockade impairs O2 extraction during progressive ischemia in pig hindlimb
Journal
J Appl Physiol (1985)
Author(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
Publication state
Published
Issued date
12/1995
Volume
79
Number
6
Pages
2035-42
Language
english
Notes
Vallet, B
Curtis, S E
Guery, B
Mangalaboyi, J
Menager, P
Cain, S M
Chopin, C
Dupuis, B A
eng
Research Support, Non-U.S. Gov't
J Appl Physiol (1985). 1995 Dec;79(6):2035-42. doi: 10.1152/jappl.1995.79.6.2035.
Abstract
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.
Keywords
Adenosine Triphosphate/*pharmacology, Animals, Hemodynamics/physiology, Hindlimb/*physiopathology, Ischemia/*physiopathology, Oxygen/*metabolism, Oxygen Consumption, Potassium Channels/*drug effects, Swine, Vascular Resistance
Pubmed
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29/04/2021 10:59
Last modification date
30/04/2021 6:38
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