Validation of a New Semi-Automated Technique to Evaluate Muscle Capillarization

The method of capillary domains has often been used to study capillarization of skeletal and heart muscle. However, the conventional data processing method using a digitizing tablet is an arduous and time-consuming task. Here we compare a new semi-automated capillary domain data collection and analysis in muscle tissue with the standard capillary domain method. The capillary density (1481±59 vs. 1447±54 caps mm(-2); R2:0.99; P<0.01) and heterogeneity of capillary spacing (0.085±0.002 vs. 0.085±0.002; R2:0.95; P<0.01) were similar in both methods. The fiber cross-sectional area correlated well between the methods (R2:0.84; P<0.01) and did not differ significantly (~8% larger in the old than new method at P=0.08). The latter was likely due to differences in outlining the contours between the two methods. In conclusion, the semi-automated method gives quantitatively and qualitatively similar data as the conventional method and saves a considerable amount of time.