MICROFILAMENT SYSTEM IN THE MICROVASCULAR ENDOTHELIUM OF THE PALMAR FASCIA AFFECTED BY MECHANICAL-STRESS APPLIED FROM OUTSIDE

The effect of externally applied mechanical stress was investigated by thin section electron microscopy of the microvessels in the unaffecte d palmar fascia in the carpal tunnel syndrome and in patients with Dup uytren's contracture before and after application of a continuous elon gation device. In the unaffected palmar fascia the microfilaments of t he endothelial cells were connected to a few adherens junctions and fo cal contacts; stress fibres were absent. In the cord of Dupuytren's di sease the microfilaments were increased in quantity. The length ratios of the connections with the lateral and basal cell membrane were sign ificantly higher than in the control group and increased to an even gr eater extent in the continuously extended fascia. Stress fibres appear ed in the endothelial cells of postcapillary venules in the nonextende d cord and in the endothelium of both arterioles and venules after ext ension elongation. The numerous intermediate filaments and the rare mi crotubules remained unchanged in the endothelial cells of all palmar f asciae analysed. In the endothelial cells of the microvessels the mech anical stress applied from outside mainly affected the contractile com ponent of the cytoskeleton.