Uptake and retention of 65Zn in lithium-treated rat liver: Role of zinc

Abstract

Aim To evaluate the effects of zinc on the biokinetics of 65Zn in rat and its distribution in various organs and in subcellular compartment following lithium therapy. Methods Female wistar rats received either lithium treatment at a dose of 1.1 g/kg in diet, zinc alone at a dose of 227 mg/L in drinking water, and combined lithium plus zinc for duration of four months. Results After four months of lithium treatment, liver enzymes increased significantly (glutamic oxaloacetic transaminase, +66.73%; glutamic pyruvic transaminase, +63.70%; alkaline phosphatase, +40.28%; p ≤ 0.001); zinc supplementation to lithium-treated rats significantly reduced liver enzymes (glutamic oxaloacetic transaminase, −13.11%; glutamic pyruvic transaminase, −21.78%; alkaline phosphatase, −11.77%; p ≤ 0.001). The biological half-lives of 65Zn showed an initial fast component (Tb 1) and a slower component (Tb 2). A significant increase in Tb 2 (38.82%, p ≤ 0.001) in liver was observed following lithium treatment, which significantly decreased following zinc treatment (21.71%, p ≤ 0.001). A significant decrease in the uptake of 65Zn (53.93%, p ≤ 0.01) in liver was observed and in nuclear ( p ≤ 0.01), mitochondrial ( p ≤ 0.01), and microsomal (52.67%, p ≤ 0.001) fractions. A significant increase in the uptake of 65Zn (82.92%, p ≤ 0.05) in liver microsomal fraction (34.09%, p ≤ 0.001) was observed in lithium-treated rats receiving zinc supplementation. Conclusion The study suggests that zinc has the potential to regulate the biokinetics of 65Zn and its subcellular distribution in rat liver following lithium therapy.