EFFECT OF INSULIN ON RADIOCHROMIUM DISTRIBUTION IN DIABETIC RATS

Chromium deficiency may result in impaired glucose tolerance. However, the converse effect of diabetes mellitus on the plasma and tissue distribution of chromium has not been clearly established. The present study was undertaken to determine the effect of experimentally induced diabetes mellitus and insulin administration on the serum and tissue distribution of radioactive chromium (51Cr) in the rat, utilizing tracer doses of 51Cr administered iv to control and diabetic rats and diabetic rats treated with insulin. A significant decrease in whole body retention of 51Cr was observed in diabetic rats, which was partially restored toward normal by insulin administration. Serum and tissue 61Cr levels were increased 30–60% and bone 51Cr was decreased 15% in rats diabetic for 31 days. Insulin administration restored the serum 51Cr level to normal and partially corrected 51 Cr distribution in certain tissues. Ratios of tissue to serum 51Cr con entration were significantly decreased 17–47% in all tissues of diabetic rats except liver, and insulin administration corrected the ratio to control levels or above. These data support the hypothesis that uncontrolled diabetes mellitus may lead to generalized depletion of body chromium, and insulin administration may protect against this loss. The reduced tissue to serum 5lCr ratios further suggest that diabetes may also lead to a disturbance in intracellular/extracellular chromium distribution which is correctable by insulin. © 1979 by The Endocrine Society.