Glucagon and insulin have opposite effects on tissue chromium distribution in an obese mouse model.

Abstract

Previous studies have suggested that chromium (Cr) is an essential cofactor for normal carbohydrate metabolism and affects insulin sensitivity, especially in rodent models. Several factors, such as insulin challenge, high carbohydrate intake, and response to stress (e.g., in obesity), alter Cr excretion or distribution. Glucagon is known to regulate carbohydrate metabolism and hyperglucagonemia plays a role in the development of hyperglycemia in diabetic subjects. In the present study we investigated possible modulation of Cr levels by glucagon using an obese mouse model. Mice were kept on a high-fat diet and then used as an obesity model. These obese mice were injected with one dose of glucagon or insulin and Cr levels in their tissues were determined. In obese mice, glucagon challenge significantly increased Cr levels in bone but decreased them in the fat and liver. In contrast, insulin challenge significantly decreased Cr levels in bone but increased them in the fat, liver and muscle. The results show that glucagon and insulin have opposite effects on Cr levels in bone, fat, liver, and muscle.