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

Abstract

Aims/Introduction: 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. Materials and Methods: 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. Results: 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. Conclusions: The results show that glucagon and insulin have opposite effects on Cr levels in bone, fat, liver, and muscle. (J Diabetes Invest,

Exercise Affects Blood Glucose Levels and Tissue Chromium Distribution in High-Fat Diet-Fed C57BL6 Mice

“…For essential metals, the bone is a physiological storage pool [4]. Chromium is released from bones and moved by the bloodstream into mobilizable pools, including the muscle, liver, and fatty tissues, which contribute to activating insulin signaling to reduce blood glucose levels [28]. Consistent with these observations, exercise promoted the movement of chromium from storage pools into glucose metabolic tissues.…”

“…These mice were grouped and fed a standard diet a high-fat diet (HFD, diet 592Z, 20.4% protein-enriched diet and modified Lab w/35.5% Lard, 1.12 ppm Cr, metabolizable energy 4.5 kcal/gm, PMI Nutrition International Inc., MO, USA) (Table S2) for 12 weeks. Generally, mice were fed a high-fat diet for 4 weeks to obtain a diet-induced obesity model [28]. Mice were housed individually in microisolation cages on high-efficiency particulate air filtered ventilated racks (Rungshin IVC Systems, Taichung, Taiwan) with a controlled temperature (22 ± 1 • C), humidity (55 ± 5%), along with a 12 hr light/dark cycle.…”

Chronic everolimus treatment of high‐fat diet mice leads to a reduction in obesity but impaired glucose tolerance

“…All feeding was ad libitum. Four weeks of an HFD are generally required to achieve a diet‐induced obesity model 22,23 . All mice were kept in the animal quarters,here, each mouse was provided an individual microisolation cage, which was placed on racks ventilated using high‐efficiency particulate air filters (Rungshin IVC Systems).…”

“…Four weeks of an HFD are generally required to achieve a diet-induced obesity model. 22,23 All mice were kept in the animal quarters,here, each mouse was provided an individual microisolation cage, which was placed on racks ventilated using high-efficiency particulate air filters (Rungshin IVC Systems). In the quarters, we applied a 12:12-h light-dark cycle, while maintaining the temperature at 22°C ± 1°C and humidity at 55% ± 5%.…”

Effects of chromium malate on glycometabolism, glycometabolism‐related enzyme levels and lipid metabolism in type 2 diabetic rats: A dose–response and curative effects study

“…Studies have shown that Cr 3+ and its complex can decrease fasting blood glucose level [12][13][14][15] . Cr can enhance insulin sensitivity and regulate lipid metabolism in diabetes 9,[16][17][18][19] .…”