Spatial distribution of capillaries in rat nerves: correlation to ischemic damage.

Computerized imaging was used to assess the spatial distribution of capillaries (number, density, and intercapillary distance) in normal rat sciatic nerve and its branches, to be able to make inferences about their distribution to central fascicular degeneration typical of ischemic nerve injury. Capillary density was significantly less in the central regions of fascicles than in outer contour areas in sciatic and proximal tibial nerves, the difference being greater in large fascicles. The mean of the minimum intercapillary distance was significantly greater in the central fascicular region of fascicles of the sciatic but not of the tibial and peroneal nerves. These anatomic characteristics may be a factor in ischemic-induced central fascicular degeneration. A decrease in the number of capillaries in a region might lead to impaired oxygen diffusion when blood flow to the region is compromised.