Muscle fiber viability, a novel method for the fast detection of ischemic muscle injury in rats.
Acute lower extremity ischemia is a limb- and life-threatening clinical problem. Rapid detection of the degree of injury is crucial, however at present there are no exact diagnostic tests available to achieve this purpose. Our goal was to examine a novel technique - which has the potential to accurately assess the degree of ischemic muscle injury within a short period of time - in a clinically relevant rodent model. Male Wistar rats were exposed to 4, 6, 8 and 9 hours of bilateral lower limb ischemia induced by the occlusion of the infrarenal aorta. Additional animals underwent 8 and 9 hours of ischemia followed by 2 hours of reperfusion to examine the effects of revascularization. Muscle samples were collected from the left anterior tibial muscle for viability assessment. The degree of muscle damage (muscle fiber viability) was assessed by morphometric evaluation of NADH-tetrazolium reductase reaction on frozen sections. Right hind limbs were perfusion-fixed with paraformaldehyde and glutaraldehyde for light and electron microscopic examinations. Muscle fiber viability decreased progressively over the time of ischemia, with significant differences found between the consecutive times. High correlation was detected between the length of ischemia and the values of muscle fiber viability. After reperfusion, viability showed significant reduction in the 8-hour-ischemia and 2-hour-reperfusion group compared to the 8-hour-ischemia-only group, and decreased further after 9 hours of ischemia and 2 hours of reperfusion. Light- and electron microscopic findings correlated strongly with the values of muscle fiber viability: lesser viability values represented higher degree of ultrastructural injury while similar viability results corresponded to similar morphological injury. Muscle fiber viability was capable of accurately determining the degree of muscle injury in our rat model. Our method might therefore be useful in clinical settings in the diagnostics of acute ischemic muscle injury.
1st Department of Surgery, Semmelweis University, Budapest, Hungary.
Zsolt
Z
Turóczi
1st Department of Surgery, Semmelweis University, Budapest, Hungary.
Péter
P
Arányi
Department of Human Morphology and Developmental Biology, Semmelweis University, Budapest, Hungary.
Ákos
Á
Lukáts
1st Department of Surgery, Semmelweis University, Budapest, Hungary.
Dávid
D
Garbaisz
2nd Department of Pathology, Semmelweis University, Budapest, Hungary.
Gábor
G
Lotz
1st Department of Surgery, Semmelweis University, Budapest, Hungary.
László
L
Harsányi
1st Department of Surgery, Semmelweis University, Budapest, Hungary.
Attila
A
Szijártó
D000818:Animals; D007511:Ischemia / Q000473:pathology* / Q000503:physiopathology; D008297:Male; D008833:Microcirculation; D018485:Muscle Fibers, Skeletal / Q000473:pathology* / Q000648:ultrastructure; D009246:NADH Tetrazolium Reductase / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D015427:Reperfusion Injury / Q000473:pathology / Q000503:physiopathology; D014022:Tissue Survival
D009246:NADH Tetrazolium Reductase