Model for Skeletal Muscle Ischemia in Rat Hindlimb: Evaluation of Reperfusion and Necrosis

Abstract

In this study we describe a technique for complete arrest of blood flow in rat hindlimbs. After graded periods of ischemia, immediate reperfusion in the leg was demonstrated by direct microscopy and scintigraphy. Laser Doppler flowmetry indicated microvascular hypoperfusion in the anterior tibial muscle during the first 2 h of reperfusion. The extent and distribution of necrosis in the middle part of the anterior tibial muscle of the legs were determined histologically 3 days after the ischemic insult. We found a reproducible degree of necrosis under constant experimental conditions. The necrosis was most pronounced in the central part of the muscle, leaving the subfascial fibers undamaged. After 4.0 h of ischemia, 46% of the cross-section area was necrotic. After 4.5 h, the necrosis increased to 70%. This difference was significant. Two types of necrotic zones were detected. One type was characterized by numerous macrophages and partial resoφtion of the muscle fibers, the other by a lack of macrophages and no resorption. Most cases with little damage had only the first type of necrosis, while most cases with extensive damage had both types. The areas that had no signs of resoφtion and therefore had been without circulation during most of the postischemic period, measured 8% after 4.0 h of ischemia and 22% after 4.5 h.

Periosteal response to transient ischemia: Histological studies on the rat tibia

“…Our model gives complete arrest of blood flow to the leg and, consequently, tissue hypoxia (Skjeldal et al 1991). The transient hypoxia may be an important factor in initiating activation of the periosteum.…”

“…We combined open clamping of the femoral artery with application of tourniquets around the proximal thigh to occlude all collateral circulation, without compression of main vessels and nerves (Skjeldal et al 1991).…”

Severe hindlimb ischemia causes periosteal proliferation in the rat tibia

“…The femoral artery was then occluded with a microvascular clip. Previous studies have shown that this technique causes complete circulatory arrest in the lower leg (Skjeldal et al 1991).…”

“…The areas of necrosis in the anterior tibial muscles were measured by morphometry, as described previously (Skjeldal et al 1991).…”

Neovascularization after ischemic injury: evaluation with 99mTc-HYNIC-RGD

“…This modality was easy, convenient and moderately reproducible. Skjeldal et al 14 reported that, small animals as like mice are endowed with a well-developed innate collateral system, and thus display remarkably high resistance to ischemia. Simple ligation of the femoral artery is known to produce no severe ischemic change.…”