title: Appropriate Insulin Level in Selecting Fortified Diet-Fed, Streptozotocin-Treated Rat Model of Type 2 Diabetes for Anti-Diabetic Studies.
abstract: BACKGROUND
  Pathophysiological investigation of disease in a suitable animal model is a classical approach towards development of a credible therapeutic strategy. This study examined appropriate insulin level in selecting animal model for type 2 diabetes (T2D) studies.
  
  
  METHODS
  Albino Wistar rats (150-200g) were divided into two groups fed with commercially available normal-diet-feed (NDF) and water or fortified diet feed (FDF) (10g NDF per gram of margarine) with 20% fructose solution as drinking water. After 6 weeks of dietary regimen both groups were divided into 5 sub-groups and injected intraperitoneally with a graded dose of streptozotocin (STZ) (0, 25, 35, 45 & 55mg/kg bw.).
  
  
  RESULTS
  The result showed that the FDF-fed rats increased significantly in body weight, basal serum insulin, total cholesterol, triglycerides and blood glucose levels as compared to NDF-fed rats. Ten days post STZ induction, the groups treated with STZ (45 & 55 mg/kg) developed frank hyperglycaemia with < 46.8% serum insulin, a severe deficiency typical of diabetes type 1. The NDF25 and NDF35 groups with 75.7% and 64.4% serum insulin respectively presented relative normoglycemia, whereas the FDF35 (85.8% serum insulin) were notably hyperglycaemia (>300 mg/dL) throughout the 6weeks post diabetes confirmation. These FDF35 rats were sensitive to glibenclamide, metformin and pioglitazone in lowering hyperglycaemia, hypertriglyceridemia and hypercholesterolemia.
  
  
  CONCLUSIONS
  The hyperglycaemia stability of the FDF35 rats (85.5% insulin) together with their sensitivity to 3 different hypoglycaemic drugs strongly suggests their suitability as a non-genetic model of T2D. Hence the study shows that circulating serum insulin ≥ 85.8% with overt hyperglycaemia may be utilized as the benchmark in selecting rat models for T2D studies.
authors.affiliation: Department of Biochemistry, Ahmadu Bello University, Zaria, Nigeria.|Directorate of Research and Development, Nigerian Institute of Leather and Science Technology, Zaria, Nigeria.
authors.forename: Stanley Irobekhian Reuben
authors.identifier: http://orcid.org/0000-0002-5471-6544
authors.initials: SI
authors.lastname: Okoduwa
authors.affiliation: Department of Biochemistry, Ahmadu Bello University, Zaria, Nigeria.
authors.forename: Ismaila A
authors.initials: IA
authors.lastname: Umar
authors.affiliation: Department of Biochemistry, Ahmadu Bello University, Zaria, Nigeria.
authors.forename: Dorcas B
authors.initials: DB
authors.lastname: James
authors.affiliation: Department of Biochemistry, Ahmadu Bello University, Zaria, Nigeria.
authors.forename: Hajiya M
authors.initials: HM
authors.lastname: Inuwa
mesh_terms: D000818:Animals; D001786:Blood Glucose; D002784:Cholesterol / Q000097:blood; D003921:Diabetes Mellitus, Experimental / Q000097:blood* / Q000178:diet therapy / Q000188:drug therapy / Q000473:pathology; D003924:Diabetes Mellitus, Type 2 / Q000097:blood* / Q000178:diet therapy / Q000188:drug therapy / Q000473:pathology; D004195:Disease Models, Animal; D005527:Food, Fortified; D006801:Humans; D006943:Hyperglycemia / Q000097:blood* / Q000178:diet therapy / Q000188:drug therapy / Q000473:pathology; D007004:Hypoglycemic Agents / Q000008:administration & dosage; D007328:Insulin / Q000097:blood*; D007333:Insulin Resistance; D008297:Male; D000077205:Pioglitazone; D051381:Rats; D017208:Rats, Wistar; D045162:Thiazolidinediones / Q000008:administration & dosage
chemical_list: D001786:Blood Glucose; D007004:Hypoglycemic Agents; D007328:Insulin; D045162:Thiazolidinediones; D002784:Cholesterol; D000077205:Pioglitazone