Nitrite increases glucose-stimulated insulin secretion and islet insulin content in obese type 2 diabetic male rats
| Autor: | Fatemeh Bakhtiarzadeh, Asghar Ghasemi, Sevda Gheibi, Homeira Zardooz, Sajad Jeddi, Khadijeh Farrokhfall |
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| Rok vydání: | 2017 |
| Předmět: |
Male
0301 basic medicine Cancer Research medicine.medical_specialty Physiology medicine.medical_treatment Clinical Biochemistry Type 2 diabetes 030204 cardiovascular system & hematology Nitric Oxide Biochemistry Diabetes Mellitus Experimental Eating Islets of Langerhans 03 medical and health sciences chemistry.chemical_compound 0302 clinical medicine Insulin resistance Internal medicine Diabetes mellitus Insulin Secretion medicine Animals Insulin Rats Wistar Nitrite Nitrites biology Chemistry Body Weight Insulin tolerance test medicine.disease Rats Glucose 030104 developmental biology Endocrinology Diabetes Mellitus Type 2 biology.protein Glycated hemoglobin Insulin Resistance GLUT4 |
| Zdroj: | Nitric Oxide. 64:39-51 |
| ISSN: | 1089-8603 |
| Popis: | Purpose Reduced bioavailability of nitric oxide (NO) is associated with pathogenesis of type 2 diabetes. Nitrite can act as a substrate for generation of systemic NO. The aim of this study was to examine the effects of nitrite administration on glucose-stimulated insulin secretion (GSIS) and islet insulin content in obese type 2 diabetic rats. Methods Male rats were divided into 4 groups: Control, control + nitrite, diabetes, and diabetes + nitrite. Sodium nitrite (50 mg/L in drinking water) was administered for 8 weeks. Diabetes was induced using high-fat diet and low-dose of streptozotocine. Serum levels of fasting glucose, insulin, and lipid profile were measured and the insulin resistance/sensitivity indices were calculated every 2 weeks. Glycated hemoglobin (HbA1C) was measured every month. At the end of the study, tissue levels of glucose transporter 4 (GLUT4) protein and serum interleukin-1 beta (IL-1β) were measured as well as glucose and insulin tolerance test were done. GSIS from isolated pancreatic islets and islet insulin content were also determined. Results Nitrite administration significantly increased insulin secretion in both control and diabetic rats in presence of 16.7 mM glucose. Nitrite also significantly increased islet insulin content by 27% and 39% in both control and diabetic rats, respectively. Nitrite decreased elevated serum IL-1β in diabetic rats (4.0 ± 0.2 vs. 2.9 ± 0.2 pg/mL, P = 0.001). In diabetic rats, nitrite also significantly increased tissue levels of GLUT4 by 22% and 26% in soleus muscle and epididymal adipose tissue, respectively. In addition, nitrite significantly improved glucose and insulin tolerance, insulin sensitivity, lipid profile, and decreased fasting glucose and insulin, but had no effect on HbA1C. Conclusions Long-term nitrite administration increased both insulin secretion and insulin content in obese type 2 diabetic rats. In addition, nitrite therapy had favorable effects on glucose tolerance, insulin resistance, inflammation, and dyslipidemia in type 2 diabetic rats. |
| Databáze: | OpenAIRE |
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