A therapeutic profile of metal chelators in the detoxication of methylmercury chloride inhibited acid and alkaline phosphatases in different areas of the central nervous system of rats.

Acid and alkaline phosphatase changes in various parts of the central nervous system (olfactory bulbs, cerebral hemispheres, cerebellum, medulla oblongata, and spinal cord) were analyzed during methylmercury chloride (MMC) treatment with a dose of 5 mg/kg/day body weight. The drug was subcutaneously introduced into the animals and the enzymes were analyzed after 2, 7, and 15 days' treatment. One group of animals was treated for seven days and kept without drug for another seven days (withdrawal group). The antagonizing capacities of four chelators, namely, N-acetyl-DL-homocysteine thiolactone (NAHT), D-penicillamine (DPA), glutathione (GSH), and sodium selenite (SEL), were also analyzed in relation to the restoration of enzymes. Study results show a linear inhibition of acid and alkaline phosphatases with increasing duration of MMC treatment. However, the magnitude of enzymatic inhibition is different in different brain areas. After 15 days' treatment, maximum inhibition of acid and alkaline phosphatases was recorded in the spinal cord and cerebellum, respectively. Chelators also exhibited differential recovery of the enzymes in various animal groups, as well as in discrete brain areas. No uniformity in the recovery of the enzymes with chelators was observed. However, study results show that biochemical parameters are good indicators of early recognition of neurotoxicity.