Effects of local extraneural application of diphtheria toxin on the sciatic nerves of normal and protein deprived rats

Abstract
Diphtheria toxin was locally administered around the sciatic nerves of normal and protein deprived rats aged 3, 6, 12, and 26 weeks in order to investigate the permeability of the barriers enveloping the nerves. At all ages the rats developed a reversible hind limb paralysis linked to a severe segmental demyelination, indicating passage of the toxin into the endoneurium. From 6 weeks of age the pattern of reaction differed between the protein deprived and control rats. The differences are discussed and interpreted as being partly dependent on less efficient protective barriers of the sciatic nerves of the protein deprived rats.