Permeability of blood nerve barriers in the diabetic rat.

An albumin-Evans blue conjugate has been used as a fluorescent tracer to demonstrate the increased permeability of endoneurial capillaries and perineurial sheath of the sciatic nerve of the alloxan-diabetic rat. The significance of the extravasation of protein into the endoneurial space is discussed in relation to the altered dynamics of the endoneurial microcirculation. It is suggested that tissue hypoxia produced in this way may be a cause of the segmental demyelination which occurs in these nerves.