title: Obesity, insulin resistance and diabetes in the sand rat exposed to a hypercaloric diet; possible protective effect for IL1-β.
abstract: It is well established that, upon changing their natural desert low caloric (succulent halophilic plants) to a regular laboratory high caloric diet, sand rats undergo various phenotypic changes depending on their genetic background and including obesity and various degrees of insulin resistance. Our aim was to investigate the acute effects of Interleukin-1β (IL-1β) and Interferon-γ (IFN-γ) on glucose-induced insulin secretion in normal lean sand rats maintained on their natural diet and in obese insulin resistant normoglycemic or type 2 diabetic animals after a 9-month high caloric diet. Animals were fed either a low or a high caloric diet; after 9 months, pancreatic islets were isolated and incubated in the presence of increasing cytokine concentrations. At the end of the high-energy diet, animals were all over-weight, and probably due to a different genetic background, they displayed either insulin resistance, hyperinsulinemia and normoglycemia or a marked type-2 diabetic state. Pancreatic islets from obese insulin resistant normoglycemic animals were much more sensitive and responsive to IL-1β when compared to lean controls. The cytokine was inefficient in diabetic islets. In conclusion, the markedly increased insulinotropic effect of IL-1β in obese diabetes-resistant sand rat could participate and be involved in pancreatic β-cell hyperactivity that compensates for insulin resistance and thereby prevent the development of type 2 diabetes in these animals.
authors.affiliation: Nutrition and Metabolism, Physiology Laboratory, USTHB, Algiers, Algeria.
authors.forename: Ali
authors.initials: A
authors.lastname: Khalkhal
authors.forename: Aomar
authors.initials: A
authors.lastname: Haddar
authors.forename: Nesrine
authors.initials: N
authors.lastname: Semiane
authors.forename: Aicha
authors.initials: A
authors.lastname: Mallek
authors.forename: Abdelouadoud
authors.initials: A
authors.lastname: Abdelmalek
authors.forename: Françoise
authors.initials: F
authors.lastname: Castex
authors.forename: René
authors.initials: R
authors.lastname: Gross
authors.forename: Yasmina
authors.initials: Y
authors.lastname: Dahmani
mesh_terms: D000818:Animals; D001786:Blood Glucose / Q000378:metabolism; D001835:Body Weight / Q000187:drug effects; D002784:Cholesterol / Q000097:blood; D003924:Diabetes Mellitus, Type 2 / Q000517:prevention & control*; D004032:Diet; D004435:Eating; D005849:Gerbillinae; D007328:Insulin / Q000097:blood; D007333:Insulin Resistance; D007371:Interferon-gamma / Q000494:pharmacology; D053583:Interleukin-1beta / Q000494:pharmacology*; D007515:Islets of Langerhans / Q000187:drug effects / Q000378:metabolism; D009765:Obesity / Q000517:prevention & control*; D051381:Rats; D017208:Rats, Wistar; D014280:Triglycerides / Q000097:blood
chemical_list: D001786:Blood Glucose; D007328:Insulin; D053583:Interleukin-1beta; D014280:Triglycerides; D007371:Interferon-gamma; D002784:Cholesterol