Influence of zinc on the biokinetics of (65)Zn in brain and whole body and its bio-distribution in aluminium-intoxicated rats.

The present study was designed to understand the influence of zinc (Zn) if any, on the biokinetics of (65)Zn in brain as well as whole body and its bio-distribution following aluminium (Al) treatment to rats. Male Sprague-Dawley rats weighing 140-160 g were divided into four different groups viz: normal control, aluminium treated (100 mg/kg b.wt./day via oral gavage), zinc treated (227 mg/L in drinking water) and combined aluminium and zinc treated. All the treatments were carried out for a total duration of 8 weeks. Al treatment showed a significant increase in fast component (Tb1) but revealed a significant decrease in slow component (Tb2) of biological half-life in brain as well as in whole body. However, Zn supplementation to Al-treated rats reversed the trend in both brain and whole body, which indicates a significant decrease in Tb1 component while the Tb2 component was significantly increased. Further, Al treatment showed an increased percent uptake value of (65)Zn in cerebrum, cerebellum, heart, liver and lungs whereas a decrease in uptake was found only in blood. On the other hand, there was a significant decline in (65)Zn activity in nuclear and mitochondrial fractions of brain of Al-treated rats. However, Zn treatment reversed the altered (65)Zn uptake values in different organs as well as in various subcellular fractions. The study demonstrates that Zn shall prove to be effective in regulating the biokinetics of (65)Zn in brain and whole body and its distribution at the tissue and subcellular levels in Al-treated rats.