Intestinal transport of zinc in the diabetic rat

Zinc has been implicated to play a role in the pathogenesis and management of diabetes. Since the intestinal transport of several minerals as calcium, magnesium and strontium was found to be altered in the diabetic rats, we postulated that intestinal zinc transport may be also altered in the diabetic rat. Therefore, using $\text{in}$$\text{vivo}$ single pass perfusion technique we determined lumen to mucosa flux, net absorption and the mucosa to lumen flux of zinc in the small and large intestinal segments of diabetic rats, diabetic rats treated with insulin and in control rats. Tissue distribution of transported ⁶⁵Zn into various organs and tissue concentrations of native zinc in the groups of rats studied were determined. Our results indicate that lumen to mucosa flux (μmole/h/g wet weight) was decreased in all intestinal segments of the diabetic rats compared to controls. However, the total capacity (mμmole/h/cm length) was similar. The specific activity and total capacity of net absorption of zinc was similar in all intestinal segments of the rats studied. The reverse mucosa to lumen flux was significantly decreased in all segments of diabetic rats compared to corresponding values in control rats. Tissue distribution of ⁶⁵Zn following the perfusion study showed increased retention of ⁶⁵Zn in the liver, kidney and femurs of the diabetic rats compared to controls. Serum and tissue concentration of native zinc in various organs were similar in all groups of rats studied. The mechanism(s) responsible for these findings are discussed.