Supplementation of zinc mitigates the altered uptake and turnover of 65Zn in liver and whole body of diabetic rats

Diabetes is a life threatening disease and its onset is linked with both environmental and genetic factors. Zinc metabolism gets altered during diabetes and results in many complications. The present study was designed to elucidate the effects of zinc supplementation on the biokinetics of Zn-65 in whole body, liver and its biodistribution in diabetic rats. The animals were divided into four groups viz; normal control; diabetic (single intraperitoneal injection of alloxan 150 mg/kg body weight); zinc treated (227 mg/l in drinking water); and diabetic + zinc treated. To carry out biokinetics study, each rat was injected intraperitoneally with 0.74 MBq radioactivity of Zn-65 following 4 weeks of different treatments and the radioactivity was determined by using a suitably shielded scintillation counter. Alloxan induced diabetic rats showed a significant decrease in both the fast (Tb-1) and slow (Tb-2) components of biological half-life of Zn-65 which, however, were normalized in whole body (P > 0.05) following zinc supplementation. In case of liver, Tb-2 component was brought back to the normal but Tb-1 component was not increased significantly. The present study indicates that the paucity of zinc in the tissues of the diabetic animals was due to decreased retention of tissue zinc as evidenced by increased serum Zn, hyperzincuria and increased rate of uptake of Zn-65 by the liver. Zinc supplementation caused a significant improvement in the retention of zinc in the tissues and is therefore likely to be of benefit in the treatment of diabetes.