title: Dietary nitrate improves glucose tolerance and lipid profile in an animal model of hyperglycemia.
abstract: Reduction in nitric oxide (NO) production and bioavailability contribute to the pathogenesis of type 2 diabetes. Administration of nitrate has strong NO-like outcomes in both animals and humans. In this study, we examined the effects of dietary nitrate on glucose tolerance and lipid profile in type 2 diabetic rats. Type 2 diabetes was induced by injection of streptozotocin and nicotinamide. Thirty-two male Wistar rats were divided into 4 groups: controls (C), control+nitrate (CN), diabetes (D), and diabetes+nitrate (DN). For 8 weeks, the CN and DN groups consumed sodium nitrate (100 mg/L in drinking water) while the C and D groups consumed tap water. Serum nitrate+nitrite (NOx), glucose, lipid profile, total antioxidant capacity (TAC), and catalase (CAT) activity were measured before and at the end of the study. Systolic blood pressure (SBP) was measured every 10 days. Intravenous glucose tolerance test (IVGTT) was performed at the end of the study. Serum NOx decreased in diabetic rats and dietary nitrate restored it to normal values. Increases in serum glucose levels was significantly lower in the DN group compared to the D group (24.1% vs. 90.2%; p < 0.05). Nitrate therapy in diabetic rats significantly improved lipid profile, glucose tolerance (AUC: 20264 ± 659 vs. 17923 ± 523; p < 0.05 for D and DN groups respectively) and restored elevated SBP to normal values. Diabetic rats had lower TAC and CAT activity and dietary nitrate restored these to normal status. In conclusion, dietary nitrate prevented increase in SBP and serum glucose, improved glucose tolerance and restored dyslipidemia in an animal model of hyperglycemia.
authors.affiliation: Department of Medical Laboratory Sciences, Faculty of Paramedical Sciences, Shahid Beheshti University of Medical Science, Tehran, Iran.
authors.forename: Saeedeh
authors.initials: S
authors.lastname: Khalifi
authors.affiliation: Department of Medical Laboratory Sciences, Faculty of Paramedical Sciences, Shahid Beheshti University of Medical Science, Tehran, Iran.
authors.forename: Ali
authors.initials: A
authors.lastname: Rahimipour
authors.affiliation: Endocrine Physiology Research Center, Research Institute for Endocrine Sciences, Shahid Beheshti University of Medical Sciences, Tehran, Iran; Endocrine Research Center, Research Institute for Endocrine Sciences, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
authors.forename: Sajad
authors.initials: S
authors.lastname: Jeddi
authors.affiliation: Endocrine Physiology Research Center, Research Institute for Endocrine Sciences, Shahid Beheshti University of Medical Sciences, Tehran, Iran; Endocrine Research Center, Research Institute for Endocrine Sciences, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
authors.forename: Mahboubeh
authors.initials: M
authors.lastname: Ghanbari
authors.affiliation: Department of Medical Laboratory Sciences, Faculty of Paramedical Sciences, Shahid Beheshti University of Medical Science, Tehran, Iran.
authors.forename: Faranak
authors.initials: F
authors.lastname: Kazerouni
authors.affiliation: Endocrine Physiology Research Center, Research Institute for Endocrine Sciences, Shahid Beheshti University of Medical Sciences, Tehran, Iran; Endocrine Research Center, Research Institute for Endocrine Sciences, Shahid Beheshti University of Medical Sciences, Tehran, Iran. Electronic address: Ghasemi@endocrine.ac.ir.
authors.forename: Asghar
authors.initials: A
authors.lastname: Ghasemi
mesh_terms: D000818:Animals; D001786:Blood Glucose / Q000187:drug effects*; D001835:Body Weight / Q000187:drug effects; D003921:Diabetes Mellitus, Experimental / Q000097:blood / Q000378:metabolism*; D004195:Disease Models, Animal; D006943:Hyperglycemia / Q000097:blood / Q000378:metabolism*; D008055:Lipids / Q000097:blood*; D008297:Male; D009566:Nitrates / Q000008:administration & dosage / Q000494:pharmacology*; D051381:Rats; D017208:Rats, Wistar; D013599:Systole / Q000187:drug effects
chemical_list: D001786:Blood Glucose; D008055:Lipids; D009566:Nitrates
keywords: Dietary nitrate; Nitric oxide; Type 2 diabetes