Abnormal subcellular distribution of GLUT4 protein in obese and insulin-treated diabetic female dogs
The GLUT4 transporter plays a key role in insulin-induced glucose uptake, which is impaired in insulin resistance. The objective of the present study was to investigate the tissue content and the subcellular distribution of GLUT4 protein in 4- to 12-year-old control, obese and insulin-treated diabet...
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| Format: | Article |
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Associação Brasileira de Divulgação Científica
2004-07-01
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| Series: | Brazilian Journal of Medical and Biological Research |
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| Online Access: | http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2004000700020 |
| _version_ | 1818016379762114560 |
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| author | A.M. Vargas R.P.A. Barros R.A. Zampieri M.M. Okamoto P. de Carvalho Papa U.F. Machado |
| author_facet | A.M. Vargas R.P.A. Barros R.A. Zampieri M.M. Okamoto P. de Carvalho Papa U.F. Machado |
| author_sort | A.M. Vargas |
| collection | DOAJ |
| description | The GLUT4 transporter plays a key role in insulin-induced glucose uptake, which is impaired in insulin resistance. The objective of the present study was to investigate the tissue content and the subcellular distribution of GLUT4 protein in 4- to 12-year-old control, obese and insulin-treated diabetic mongrel female dogs (4 animals per group). The parametrial white adipose tissue was sampled and processed to obtain both plasma membrane and microsome subcellular fractions for GLUT4 analysis by Western blotting. There was no significant difference in glycemia and insulinemia between control and obese animals. Diabetic dogs showed hyperglycemia (369.9 ± 89.9 mg/dl). Compared to control, the plasma membrane GLUT4, reported per g tissue, was reduced by 55% (P < 0.01) in obese dogs, and increased by 30% (P < 0.05) in diabetic dogs, and the microsomal GLUT4 was increased by ~45% (P < 0.001) in both obese and diabetic animals. Considering the sum of GLUT4 measured in plasma membrane and microsome as total cellular GLUT4, percent GLUT4 present in plasma membrane was reduced by ~65% (P < 0.001) in obese compared to control and diabetic animals. Since insulin stimulates GLUT4 translocation to the plasma membrane, percent GLUT4 in plasma membrane was divided by the insulinemia at the time of tissue removal and was found to be reduced by 75% (P < 0.01) in obese compared to control dogs. We conclude that the insulin-stimulated translocation of GLUT4 to the cell surface is reduced in obese female dogs. This probably contributes to insulin resistance, which plays an important role in glucose homeostasis in dogs. |
| first_indexed | 2024-04-14T07:12:37Z |
| format | Article |
| id | doaj.art-65d6a3c6b67b4cd19928d680de823aac |
| institution | Directory Open Access Journal |
| issn | 0100-879X 1414-431X |
| language | English |
| last_indexed | 2024-04-14T07:12:37Z |
| publishDate | 2004-07-01 |
| publisher | Associação Brasileira de Divulgação Científica |
| record_format | Article |
| series | Brazilian Journal of Medical and Biological Research |
| spelling | doaj.art-65d6a3c6b67b4cd19928d680de823aac2022-12-22T02:06:24ZengAssociação Brasileira de Divulgação CientíficaBrazilian Journal of Medical and Biological Research0100-879X1414-431X2004-07-013771095110110.1590/S0100-879X2004000700020Abnormal subcellular distribution of GLUT4 protein in obese and insulin-treated diabetic female dogsA.M. VargasR.P.A. BarrosR.A. ZampieriM.M. OkamotoP. de Carvalho PapaU.F. MachadoThe GLUT4 transporter plays a key role in insulin-induced glucose uptake, which is impaired in insulin resistance. The objective of the present study was to investigate the tissue content and the subcellular distribution of GLUT4 protein in 4- to 12-year-old control, obese and insulin-treated diabetic mongrel female dogs (4 animals per group). The parametrial white adipose tissue was sampled and processed to obtain both plasma membrane and microsome subcellular fractions for GLUT4 analysis by Western blotting. There was no significant difference in glycemia and insulinemia between control and obese animals. Diabetic dogs showed hyperglycemia (369.9 ± 89.9 mg/dl). Compared to control, the plasma membrane GLUT4, reported per g tissue, was reduced by 55% (P < 0.01) in obese dogs, and increased by 30% (P < 0.05) in diabetic dogs, and the microsomal GLUT4 was increased by ~45% (P < 0.001) in both obese and diabetic animals. Considering the sum of GLUT4 measured in plasma membrane and microsome as total cellular GLUT4, percent GLUT4 present in plasma membrane was reduced by ~65% (P < 0.001) in obese compared to control and diabetic animals. Since insulin stimulates GLUT4 translocation to the plasma membrane, percent GLUT4 in plasma membrane was divided by the insulinemia at the time of tissue removal and was found to be reduced by 75% (P < 0.01) in obese compared to control dogs. We conclude that the insulin-stimulated translocation of GLUT4 to the cell surface is reduced in obese female dogs. This probably contributes to insulin resistance, which plays an important role in glucose homeostasis in dogs.http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2004000700020DiabetesObesityInsulin resistanceGLUT4Adipose tissuePlasma membrane |
| spellingShingle | A.M. Vargas R.P.A. Barros R.A. Zampieri M.M. Okamoto P. de Carvalho Papa U.F. Machado Abnormal subcellular distribution of GLUT4 protein in obese and insulin-treated diabetic female dogs Brazilian Journal of Medical and Biological Research Diabetes Obesity Insulin resistance GLUT4 Adipose tissue Plasma membrane |
| title | Abnormal subcellular distribution of GLUT4 protein in obese and insulin-treated diabetic female dogs |
| title_full | Abnormal subcellular distribution of GLUT4 protein in obese and insulin-treated diabetic female dogs |
| title_fullStr | Abnormal subcellular distribution of GLUT4 protein in obese and insulin-treated diabetic female dogs |
| title_full_unstemmed | Abnormal subcellular distribution of GLUT4 protein in obese and insulin-treated diabetic female dogs |
| title_short | Abnormal subcellular distribution of GLUT4 protein in obese and insulin-treated diabetic female dogs |
| title_sort | abnormal subcellular distribution of glut4 protein in obese and insulin treated diabetic female dogs |
| topic | Diabetes Obesity Insulin resistance GLUT4 Adipose tissue Plasma membrane |
| url | http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2004000700020 |
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