Skeletal muscle microvascular and tissue injury after varying durations of ischemia

Abstract

The purpose of this study was to examine the effect of varying durations of ischemia on several microvascular parameters in the awake hamster chamber model. The goal was to characterize the microvascular damage that occurs in skeletal muscle as a result of ischemia and reperfusion. The chamber tissues were subjected to 1-5 h of ischemia, and then the following parameters were measured: vessel diameter, endothelial thickness, macromolecular leakage, red blood cell velocity, adherent leukocytes, rolling leukocytes, freely flowing leukocytes, functional capillary density, and propidium iodide-positive cell nuclei. In control animals there was no significant difference in any parameters over the entire observation period. After 1 or 2 h of ischemia an increase in rolling and adherent leukocytes was measured. After 3 h of ischemia there was a significant increase in the mean endothelial thickness and in the number of nonviable cells. After 4 h of ischemia a significant difference in the extent of macromolecular leakage and the functional capillary density was additionally observed. After 5 h of ischemia this damage was more pronounced and often so severe that approximately 50% of the vessels demonstrated no reflow.

Neovascularization of poly(ether ester) block‐copolymer scaffolds in vivo: Long‐term investigations using intravital fluorescent microscopy

“…22 In the current study, using scaffolds prepared with the block copolymer PEGT and PBT, FITC-dextran leakage at border zone of the scaffolds was similar to that in the surrounding tissue. This can be interpreted as an absence of inflammatory reaction to the biomaterial used.…”

“…22,34 This can be interpreted as proof of the stability of the model used. The model also allows evaluation of inflammatory/foreign body response to the scaffold material.…”

“…22 It is calculated as the ratio between the fluorescence intensity measured inside versus outside a vessel. Diameter measurements provide information about changes of local microangiodynamics, for example, during ischemia/reperfusion or wound healing.…”

Ischemia-Reperfusion Injury in the Transplanted Kidney Based on Purine Metabolism Markers and Activity of the Antioxidant System

“…These include alterations in mitochondrial electron transport, arachidonic acid metabolism, activation of xanthine oxidase, catecholamines or haemoglobin oxidation, as well as massive release of iron (Jassem et al, 2002). The results from previous studies indicate that leucocytes play a key role in ischaemia-reperfusion injury (Harris et al, 1996). The phenomenon also involves components of a typical inflammatory reaction.…”

Neutrophil leukocyte-mediated inflammatory reactions in the periosteum and synovial membrane

“…The number of recruited PMNs and the extent of tissue damage during IR are interrelated phenomena (Harris 1996). At the beginning of this process, ROS-dependent direct endothelial damage occurs and the damaged/activated endothelial cells produce chemoattractants such as platelet-activating factor, leukotriene B4 and chemokines on their luminar surface thereby promoting the chemotaxic movement of PMNs (Kurose 1997;Wanner 1996).…”