Structural and Functional Abnormalities in the Islets Isolated From Type 2 Diabetic Subjects.
Deng, Shaoping 1; Vatamaniuk, Marko 2,3; Huang, Xiaolun 1; Doliba, Nicolai 2,3; Lian, Moh-Moh 1; Frank, Adam 1; Velidedeoglu, Ergun 1; Desai, Niraj M. 1; Koeberlein, Brigitte 1; Wolf, Bryan 4; Barker, Clyde F. 1; Naji, Ali 1; Matschinsky, Franz M. 2,3; Markmann, James F. 1
[Miscellaneous Article] Diabetes. 53(3):624-632, March 2004.

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Type 2 diabetic subjects manifest both disordered insulin action and abnormalities in their pancreatic islet cells. Whether the latter represents a primary defect or is a consequence of the former is unknown. To examine the [beta]-cell mass and function of islets from type 2 diabetic patients directly, we isolated islets from pancreata of type 2 diabetic cadaveric donors (n = 14) and compared them with islets from normal donors (n = 14) matched for age, BMI, and cold ischemia time. The total recovered islet mass from type 2 diabetic pancreata was significantly less than that from nondiabetic control subjects (256,260 islet equivalents [2,588 IEq/g pancreas] versus 597,569 islet equivalents [6,037 IEq/g pancreas]). Type 2 diabetic islets were also noted to be smaller on average, and histologically, islets from diabetic patients contained a higher proportion of glucagon-producing [alpha]-cells. In vitro study of islet function from diabetic patients revealed an abnormal glucose-stimulated insulin release response in perifusion assays. In addition, in comparison with normal islets, an equivalent number of type 2 diabetic islets failed to reverse hyperglycemia when transplanted to immunodeficient diabetic mice. These results provide direct evidence for abnormalities in the islets of type 2 diabetic patients that may contribute to the pathogenesis of the disease.

(C) 2004 by the American Diabetes Association, Inc.