Skeletal muscle microcirculation: the effects of limited blood supply and treatment with torbafylline.

The effects of one and two week arterial occlusion on the microcirculation of fast glycolytic skeletal muscle (rat tibialis anterior) were assessed by direct observation. Ligation of the right common iliac artery resulted in a greater proportion of the capillary population exhibiting intermittent flow, and reduction of capillary diameters. Terminal arterioles showed a lack of responsiveness to acute contractions of the muscle, while those in control muscles dilated. Acute infusion of torbafylline reduced the heterogeneity of flow by reducing the population of capillaries with intermittent flow and the time spent stationary by red cells. It also improved the pO2 at the muscle surface. Chronic oral administration of torbafylline for one week, started one week post-ligation, resulted in a similar response of the arterioles to muscle contractions as in control muscles and marginally improved the heterogeneity of flow.