Acute lead intoxication in vivo affects myelin membrane morphology and CNPase activity

The aim of the present study was to assess the sensitivity of central nervous system myelin to acute Pb-toxicity in an animal model, that imitates lead toxicity in occupationally exposed workers, or in occasional incidents of poisoning. Our results indicated that in vivo acute lead intoxication affected both the morphology of myelin and enzymatic activity of the myelin marker, CNPase (2'3'-cyclic nucleotide 3'-phosphodiesterase). The multilayered structure of myelin sheaths was regionally disturbed, with loosely arranged membranes or ovoid-shaped swollen fragments. The activity of CNPase was diminished and Michaelis-Menten kinetics showed a decreased affinity and lower velocity of the enzyme. These data suggest that the disturbances in CNPase activity may contribute, in some extent, to the changes in myelin morphology observed in acute Pb-intoxication.