Neonatal streptozotocin-induced diabetes mellitus: a model of insulin resistance associated with loss of adipose mass
| Autor: | Sandra Andreotti, M. A. Machado, Luciana Brito, Julie Takada, Miriam H. Fonseca-Alaniz, Sidney B. Peres, Fábio Bessa Lima, Cristina das Neves Borges-Silva, Cecília Edna Mareze da Costa |
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| Rok vydání: | 2007 |
| Předmět: |
Blood Glucose
Male Glycosuria medicine.medical_specialty endocrine system diseases Endocrinology Diabetes and Metabolism medicine.medical_treatment Streptozocin Diabetes Mellitus Experimental Impaired glucose tolerance Endocrinology Insulin resistance Internal medicine Diabetes mellitus medicine Animals Insulin Rats Wistar Glucose tolerance test biology medicine.diagnostic_test business.industry Glucose Tolerance Test medicine.disease Rats Disease Models Animal Insulin receptor Glucose Adipose Tissue Animals Newborn biology.protein Insulin Resistance medicine.symptom business Polydipsia |
| Zdroj: | Metabolism. 56:977-984 |
| ISSN: | 0026-0495 |
| Popis: | The use of experimental models of diabetes mellitus (DM) has been useful in understanding the complex pathogenesis of DM. Streptozotocin (STZ) injected in rats during the neonatal period has usually led to the major features described in diabetic patients (hyperglycemia, polyphagia, polydipsia, polyuria, and abnormal glucose tolerance) in a short period. Diabetes mellitus is a product of low insulin sensibility and pancreatic beta-cell dysfunction. Its process is characterized by a symptomless prediabetic phase before the development of the disease. In this study, we investigated the long-term effects of diabetes induction regarding the cellular metabolic aspects of this model and its similarities with diabetes found in humans. Male Wistar rats (5-day old) were intraperitoneally injected with STZ (150 mg/kg) and followed up for 12 weeks. On the 12th week, animals were decapitated and peri-epididymal fat pads were excised for adipocyte isolation. The following studies were performed: insulin-stimulated 2-deoxy-d-[(3)H]glucose uptake; incorporation of d-[U-(14)C]-glucose into lipids and conversion into (14)CO(2); and insulin binding. The weight gain rate of the STZ-treated group became significantly lower by the eighth week. These rats developed polyphagia, polydipsia, polyuria, and glycosuria, and impaired glucose tolerance. Biological tests with isolated adipocytes revealed a reduction in the insulin receptor number and an impairment in their ability to oxidize glucose as well as to incorporate it into lipids. Interestingly, parallel to reduced body weight, the adipocyte size of STZ rats was significantly small. We concluded that apart of a decrease in pancreatic insulin content, this experimental model of DM promotes a remarkable and sustained picture of insulin resistance in adulthood that is strongly related to a loss in adipose mass. |
| Databáze: | OpenAIRE |
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