title: The effect of experimentally induced chronic hyperglycaemia on serum and pancreatic insulin, pancreatic islet IGF-I and plasma and urinary ketones in the domestic cat (Felis felis).
abstract: Like in humans, diabetes mellitus is on the rise in cats. Feline diabetes is a suitable model for human type-2 diabetes. We investigated magnitude and timing of insulin suppression with induced hyperglycaemia and its relationship to plasma and urinary ketones and to pancreatic islet insulin. IGF-I is under discussion as a protective mechanism but little is known about its role in diabetes in general and its distinct localisation in feline pancreatic islets in particular. Thirteen healthy, adult cats were allocated to 2 groups and infused with glucose to maintain their blood glucose at a high or moderate concentration for 42 days resulting in insulin secretion suppression. After initial increase, insulin levels declined to baseline but were still detectable in the blood at a very low level after 6 weeks of glucose infusion and then increased after a 3 week recovery period. While IGF-I in healthy cats was primarily located in glucagon cells, in hyperglycaemia-challenge IGF-I was pronounced in the β-cells 3 weeks after ceasation of infusion. Six/8 cats developing glucose toxicity became ketonuric after 3-4 weeks. Gross lipaemia occurred approx 1 week prior to ketonuria. Ketonuric cats required 1-2 weeks of insulin therapy after-infusion until β-cell recovery. In conclusion, ketosis and hyperlipidaemia are likely to occur in diabetic cats with glucose at 30 mmol/L, especially after ≥2 weeks. Three weeks after ceasation of infusions, clinical and morphological recovery occurred. We propose a local protective effect of IGF-I to support survival and insulin production in the hyperglycaemic state and recovery period.
authors: Centre for Evolutionary Medicine (ZEM), Institute of Anatomy, University of Zurich, Zurich, Switzerland.
authors: Karl R J
authors: KR
authors: Link
authors: Ileana
authors: I
authors: Allio
authors: Jacqueline S
authors: JS
authors: Rand
authors: Elisabeth
authors: E
authors: Eppler
mesh_terms: D000818:Animals; D002415:Cats; D006943:Hyperglycemia / Q000097:blood* / Q000378:metabolism*; D007328:Insulin / Q000097:blood* / Q000378:metabolism*; D007334:Insulin-Like Growth Factor I / Q000378:metabolism*; D050417:Insulin-Secreting Cells / Q000378:metabolism; D007515:Islets of Langerhans / Q000378:metabolism*; D007659:Ketones / Q000097:blood* / Q000652:urine*
chemical_list: D007328:Insulin; D007659:Ketones; D007334:Insulin-Like Growth Factor I