The enhancement of revascularisation of skeletal muscle transplants using the beta 2-agonist isoprenaline.

The effect of the beta 2-agonist isoprenaline on the revascularisation and regeneration of skeletal muscle transplants was studied using histological, morphometric and autoradiographic methods. Revascularisation of the transplants was accelerated in the isoprenaline-treated mice as evidenced by histological and autoradiographic results. The numbers of presumptive satellite cells were increased in the isoprenaline-treated mice. Significant increases in muscle cytoplasmic volume, endothelial cell volume, capillary and myofibre numbers, and the numbers of myofibres with peripheral nuclei were also found in transplants removed from the isoprenaline-treated mice (compared with controls). Reductions in myonuclear volume, 'other tissue' volume and numbers of myofibres with no nucleus sectioned were also found in transplants from isoprenaline-treated mice. Although there was an increased volume of regenerated muscle in the transplants, it cannot be concluded that this was because of the earlier transplant revascularisation, as beta 2-agonists have been shown to have a hypertrophic effect on skeletal muscle.