Compartmental analysis of zinc kinetics in mature male rats

A compartmental model of zinc kinetics in mature male rats was developed. The model was based on zinc and radioisotopic zinc measured in samples of plasma, skeletal muscle, kidneys, testes, spleen, bone, and intestinal segments collected at various times for up to 4 days after 65Zn was injected intravenously. Zinc intake, excretion of zinc and 65Zn in urine and feces, and the whole body retention of 65Zn were also determined. Other data used to develop the model included published information on zinc concentration and zinc kinetics in tissues that were not sampled. In the model, the intestinal tract was represented by five compartments. Plasma, spleen, kidneys, and testes were each represented by an individual compartment. In contrast, two compartments each were used to represent exchangeable zinc in liver, bone, skeletal muscle, skin, and red blood cells. The present model extends earlier models of zinc kinetics, describes the distribution of zinc in the whole body, and may provide a means to evaluate the influence of either pathophysiological conditions or dietary extremes on the metabolism of zinc.