Disturbed α-Cell Function in Mice with β-Cell Specific Overexpression of Human Islet Amyloid Polypeptide. (23rd June 2008)

• Record Type: Journal Article
• Authors: Ahrén, Bo; Sörhede Winzell, Maria
• Other Names: Westermark Per Academic Editor.
• Is Part Of: Experimental diabetes research. Volume 2008(2008)
• Publication Date: 2008-06-23
• Subjects: Diabetes -- Research -- Periodicals; Diabetes -- Research; Periodicals; 616.462
• DOI: 10.1155/2008/304513
• Languages: English
• ISSNs: 1687-5214

Abstract

Abstract : Exogenous administration of islet amyloid polypeptide (IAPP) has been shown to inhibit both insulin and glucagon secretion. This study examinedα -cell function in mice withβ -cell specific overexpression of human IAPP (hIAPP) after an oral protein gavage (75 mg whey protein/mouse). Baseline glucagon levels were higher in transgenic mice (41± 4.0 pg/mL, n = 6 ) than in wildtype animals (19± 5.1 pg/mL, n = 5, P = .015 ). In contrast, the glucagon response to protein was impaired in transgenic animals (21± 2.7 pg/mL in transgenic mice versus 38± 5.7 pg/mL in wildtype mice at 15 minutes;P = .027 ). Baseline insulin levels did not differ between the groups, while the insulin response, as the glucagon response, was impaired after protein challenge (P = .018 ). Glucose levels were not different between the groups and did not change significantly after protein gavage. Acetaminophen was given through gavage to the animals (2 mg/mouse) to estimate gastric emptying. The plasma acetaminophen profile was similar in the two groups of mice. We conclude that disturbances in glucagon secretion exist in mice withβ -cell specific overexpression of human IAPP, which are not secondary to changes in gastric emptying. The reduced glucagon response to protein challenge may reflect a direct inhibitory influence of hIAPP on glucagon secretion.