Effect of Manganese on energy metabolism in young and adult rat brain: Ameliorating effect of Alpha-Tocopherol

Trace amounts of Manganese (Mn) are essential for the proper functioning of a variety of physiological processes, including development, in all living organisms. However, several studies indicate that high Mn levels may be toxic to terrestrial and aquatic organisms, especially due to its neurotoxic properties. In the present study, the young and adult albino rats (2 months and 4 months old) were exposed to low dose (2.5mg/kg body weight) and high dose (5mg/kg body weight) of Mn through intraperitoneal injection for a period of 3 weeks and a separate batch treated with Mn was left for a period of one week supplementation with Alpha-tocopherol at a dose of 5mg/kg body weightalong with Mn until the end of the study.Control animals received only deionized water without Mn. In the present study, it was observed that, the potential effect of Adenosine Triphosphatase (ATPase) activity (EC 3.6.1.3); Mg2+ATPase and Na+K+ ATPase activities were assayed. From our observation, it was cleared that the Mg2+ATPase and Na+K+ ATPase activities were decreased in synaptosomal fraction at both 2 months and 4 months old rats at both concentrations (i.e. 2.5 mg/kg bw and 5 mg/kg bw) when compared to control rats. The adult rats showed greater frequency of Mg2+ATPase activity compared to young rats. However, the high dose (5 mg/kg bw) of Mn treated rats of both age groups showed decreased Mg2+ATPase activity compared to low dose (2.5 mg/kg bw) of Mn treated rats. Whereas, the rats supplemented with Alpha-tocopherol along with Mn showed gradual increase in Mg2+ATPase and Na+K+ATPase activities respectively. In addition to this, we have also examined the body weights of 2 months and 4 months old rats at both low dose and high dose of Mn and Alpha-tocopherol also. In this, it was clear that, the low and high dose Mn exposed rats showed decrease in their body weights at both ages (2 and 4 months) as compared to control. Decrease in body weights were higher in high dose exposure compared to low dose. However, partial recovery of body weights were observed in Alpha-tocopherol Supplemented rats at both ages in high dose and low dose of Mn exposure. The above findings suggest that short-term Mn in vivo administration causes a statistically significant decrease in energy metabolism and body weights. The Mn toxicity was reversed with Alpha-tocopherol co-administration which could thus be considered for future applications as a neuroprotective agent against chronic exposure to Mn and the treatment of manganism.