Plasma proteins in human peripheral nerve.

Using the immunofluorescent technique, the distribution of nine plasma proteins, differing in molecular weight, was studied in sural nerve biopsies from 25 neurological patients. The results of this study show that endoneurial vessels are normally permeable to all plasma proteins, though not to an equal degree. Permeability of the nerve blood vessels may be increased in pathological conditions. Proteins of molecular weight equal to or greater than 340,000 tend to accumulate at the site of the perineurium, indicating a slow removal from this structure. A marked accumulation of plasma proteins at the site of the perineurium was observed in hypertrophic neuropathy.