Effects of the presence, absence, and overexpression of uncoupling protein-3 on adiposity and fuel metabolism in congenic mice
| Autor: | Shehla N. Chaudhry, Mahmoud Salkhordeh, Mary-Ellen Harper, Sheila R. Costford |
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| Rok vydání: | 2006 |
| Předmět: |
Male
medicine.medical_specialty Physiology Endocrinology Diabetes and Metabolism Congenic Biology Ion Channels Quadriceps Muscle Mitochondrial Proteins Mice Mice Congenic Oxygen Consumption Insulin resistance Adipose Tissue Brown Physiology (medical) Internal medicine medicine Animals Uncoupling Protein 3 Uncoupling protein Presence absence Muscle Skeletal Inner mitochondrial membrane Adiposity UCP3 Mice Knockout Skeletal muscle Organ Size Metabolism Glucose Tolerance Test medicine.disease Mice Inbred C57BL Glucose medicine.anatomical_structure Endocrinology Liver Carrier Proteins Energy Metabolism |
| Zdroj: | American Journal of Physiology-Endocrinology and Metabolism. 290:E1304-E1312 |
| ISSN: | 1522-1555 0193-1849 |
| DOI: | 10.1152/ajpendo.00401.2005 |
| Popis: | Uncoupling protein-3 (UCP3) is a poorly understood mitochondrial inner membrane protein expressed predominantly in skeletal muscle. The aim of this study was to examine the effects of the absence or constitutive physiological overexpression of UCP3 on whole body energy metabolism, glucose tolerance, and muscle triglyceride content. Congenic male UCP3 knockout mice ( Ucp3 −/−), wild-type, and transgenic UCP3 overexpressing (UCP3Tg) mice were fed a 10% fat diet for 4 or 8 mo after they were weaned. UCP3Tg mice had lower body weights and were less metabolically efficient than wild-type or Ucp3 −/− mice, but they were not hyperphagic. UCP3Tg mice had smaller epididymal white adipose tissue and brown adipose tissue (BAT) depots; however, there were no differences in muscle weights. Glucose and insulin tolerance tests revealed that both UCP3Tg and Ucp3 −/− mice were protected from development of impaired glucose tolerance and were more sensitive to insulin. 2-Deoxy-d-[1-3H]glucose tracer studies showed increased uptake of glucose into BAT and increased storage of liver glycogen in Ucp3 −/− mice. Assessments of intramuscular triglyceride (IMTG) revealed decreases in quadriceps of UCP3Tg mice compared with wild-type and Ucp3 −/− mice. When challenged with a 45% fat diet, Ucp3 −/− mice showed increased accumulation of IMTG compared with wild-type mice, which in turn had greater IMTG than UCP3Tg mice. Results are consistent with a role for UCP3 in preventing accumulation of triglyceride in both adipose tissue and muscle. |
| Databáze: | OpenAIRE |
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