CNPase activity in myelin from adult rat brains after prolonged lead exposure in vivo.
The present study investigated the sensitivity of rats cerebral myelin to prolonged toxicity of lead (Pb) that imitates environmental exposure to this metal. The results indicated that 90 days exposure of young adult rats to lead in drinking water affects the morphology of myelin sheaths, expressed in disintegration of its multilamellar structure. Both, the protein content and the activity of the myelin-specific enzyme CNPase (2',3'-cyclic nucleotide 3-phosphodiesterase), were lowered. The Michaelis-Menten kinetic for CNPase in myelin obtained from control and Pb-treated rats was different. Km increased and Vmax decreased when compared to controls. Observed disturbances in enzyme activity may be one of the potential reasons of the ultrastructural changes. It is thus tempting to speculate that Pb may be considered as a one of the factors contributing to demyelinating diseases.
Dabrowska-Bouta
Beata
B
Laboratory of Pathobiochemistry of the Central Nervous System, Department of Neurochemistry, Medical Research Centre, Polish Academy of Sciences, 5 Pawińskiego St., 02-106 Warsaw, Poland.
Sulkowski
Grzegorz
G
Struzyńska
Lidia
L
Rafałowska
Urszula
U
D015087:2',3'-Cyclic-Nucleotide Phosphodiesterases / Q000378:metabolism*; D000818:Animals; D001921:Brain / Q000201:enzymology*; D007700:Kinetics; D007855:Lead Poisoning / Q000201:enzymology*; D008297:Male; D009186:Myelin Sheath / Q000201:enzymology* / Q000648:ultrastructure; D009412:Nerve Fibers / Q000201:enzymology / Q000648:ultrastructure; D051381:Rats; D017208:Rats, Wistar
D015087:2',3'-Cyclic-Nucleotide Phosphodiesterases