Regulatory role of zinc on the altered biokinetics of 65Zn during arsenic induced hepatotoxicity

Objectives The present study was designed to elucidate the regulatory role of zinc on the biokinetics of 65Zn in arsenic intoxicated rats.

Methods The animals were segregated into four groups viz. Group I: untreated controls, Group II: Arsenic treated (100 ppm as NaAsO2 in drinking water), Group III: zinc treated (227 mg ZnSO4/L drinking water) and Group IV: arsenic + zinc treated. Each rat was injected intraperitoneally with 1.85 MBq radioactivity of 65Zn following three months of different treatments and the counts were recorded by using a suitably shielded scintillation counter. All the rats were injected with 0.37 MBq radioactivity of 65Zn, a day prior to sacrificing them.

Results A significant increase was found in the fast component (Tb1) of biological half life of 65Zn in liver of arsenic treated rats but no significant change was noticed in fast component in the whole body. Further, arsenic treatment resulted in a significant decrease in the slow component (Tb2) of 65Zn in the whole body but did not cause any significant change in Tb2 in liver. However, zinc supplementation to arsenic treated rats was able to normalize the fast component in case of liver but it was not able to bring any significant change in the slow component of 65Zn in the whole body. Further, the uptake values of 65Zn were significantly increased in the liver, brain, kidney and intestine of arsenic treated rats as compared to normal controls. However, zinc supplementation to arsenic treated rats was able to significantly decrease the already elevated uptake values only in the liver and brain.

Conclusions In conclusion, zinc provides protection against arsenic induced hepatotoxicity by regulating the altered biokinetics of 65Zn.

Research Support ICMR, Indi