Impaired development of the rat perineurium by undernutrition. An enzyme histochemical study.

Enzyme activity of adenosinetriphosphatase, NADH2-tetrazolium reductase and lactate dehydrogenase was studied in the rat perineurium 10, 20, 30, and 90 days post partum. The effect of undernutrition was shown by a lack of enzyme activity in rats 30 days post partum in contrast to control animals. 30 days also corresponds to the time when, in normal rats, the perineurial diffusion barrier to exogenous macromolecules becomes established. In undernourished rats this diffusion barrier does not appear. At 90 days post partum raised enzyme activities indicate a high metabolic turnover in the perineurium even in animals with undernutrition.