Characterization of microvascular vasoconstriction following ischemia/reperfusion in skeletal muscle using videomicroscopy.
This study investigated the possible contribution of microvascular vasoconstriction to no-reflow following ischemia/reperfusion in a mouse skeletal muscle model. Using paired cremaster muscles, arterioles of diameter 10-100 microns were directly viewed and measured by the use of an in vivo videomicroscopy before and after a 6-hr period of complete ischemia at 27 degrees C. Following ischemia/reperfusion, feeder and arcading arterioles constricted significantly to 54.5 and 62% of pre-ischemic baseline diameters respectively (P < .05). While the calcium antagonist diltiazem and nitroprusside were both able to reverse arteriolar constriction, endothelium-dependent acetylcholine-induced dilatation was markedly impaired following reperfusion (P < 0.05). Superoxide dismutase did not attenuate the microvascular response, suggesting that the mechanism is likely to be at least partly free radical-independent.
Department of Surgery, Leicester Royal Infirmary, United Kingdom.
M
M
Pemberton
G L
GL
Anderson
J H
JH
Barker
D000109:Acetylcholine / Q000494:pharmacology; D000818:Animals; D002121:Calcium Channel Blockers / Q000494:pharmacology; D004110:Diltiazem / Q000494:pharmacology; D004727:Endothelium / Q000502:physiology; D008297:Male; D051379:Mice; D008833:Microcirculation / Q000187:drug effects / Q000502:physiology*; D018715:Microscopy, Video; D009132:Muscles / Q000098:blood supply*; D009599:Nitroprusside / Q000494:pharmacology; D015427:Reperfusion Injury / Q000503:physiopathology*; D013482:Superoxide Dismutase / Q000494:pharmacology; D014661:Vasoconstriction / Q000502:physiology*; D014665:Vasodilator Agents / Q000494:pharmacology
D002121:Calcium Channel Blockers; D014665:Vasodilator Agents; D009599:Nitroprusside; D013482:Superoxide Dismutase; D004110:Diltiazem; D000109:Acetylcholine