An angiogenic extract from skeletal muscle stimulates monocyte and endothelial cell chemotaxis in vitro

The purpose of this study was to determine whether the extraction of skeletal muscle with a combination of ethanol and hydrochloric acid yields a product capable of stimulating angiogenesis. The resulting extract stimulated inflammation in the rabbit corneal assay, which was followed by capillary formation. In order to determine whether the observed angiogenesis was stimulated by a factor(s) acting directly on the endothelial cells versus a factor(s) recruiting macrophages that in turn release factors acting on endothelial cells, the muscle extract was tested for endothelial cell and monocyte chemotaxis activity in vitro. The muscle extract stimulated significant endothelial cell chemotaxis at concentrations between 94 and 750 micrograms of protein/ml and significant monocyte chemotaxis at concentrations between 8 and 75 micrograms of protein/ml. Polyacrylamide gel electrophoresis suggests that basic fibroblast growth factor and transforming growth factor-beta may be present in this acid/ethanol extract of skeletal muscle.