Chromium(Cr)is an essential trace element for normal carbohydrate metabolism, and its deficiency in animals can cause a diabetic-like state. Human and experimental animal studies suggest that urinary Cr excretion is increased in diabetic patients. To investigate whether hyperglycemia-induced elevation of urinary Cr excretion at relatively early stages of diabetes reduces tissue Cr storage, we assessed Cr excretion and Cr distribution in streptozotocin(STZ)-induced diabetic mice. Male C57BL mice were randomly assigned to STZ or control groups. STZ mice were injected with STZ to induce insulin-dependent diabetes(day 0)and 24-hour urinary collections were taken 3, 4 and 5 days after the STZ treatment. An inductively coupled plasma mass spectrometer equipped with a dynamic reaction cell was used for the determination of Cr in urine, plasma and tissue samples. The urinary Cr concentration and urine volume in the STZ-treated mice on day 5 after STZ injection was approximately∼3 times and 7 times higher than those of control. STZ-induced diabetic mice excreted 35-fold Cr compared to control mice, during 5 days after STZ injection. The renal Cr concentrations in STZ-induced diabetic mice were significantly lower than those in controls(p < 0.05). These results suggested that hyperglycemia by STZ increased urinary Cr output and caused reduction of renal Cr concentration.
