Striated muscle capillaries in uremic patients and in renal transplant recipients.

With the use of light and electron microscopic and morphometric methods, we studied the gastrocnemius muscle capillaries in nine uremic patients and eight renal transplant recipients. Observations of intramuscular microangiopathy, eg, thickening and remnants of the capillary basement membrane (BM) and vacuolation of endothelial cells, were prominent in both patient groups. In morphometric analysis, the mean BM fraction of the total capillary area was larger, and the capillary lumen was smaller, in the uremic patients and in the renal transplant recipients than in the normal control subjects. The capillary-to-fiber ratio was higher in the patients with transplants than in the uremic patients or in the normal control subjects.