Liberase HI has many advantages over traditional collagenases. Liberase performs the rapid dissociation of human pancreata and allows for the preservation of the morphological and functional integrity of isolated islets. The aim of this study was to investigate the effect of different concentrations of Liberase HI (1.5, 2.5 and 3.5 mg/ml) on the yield, viability and function of islets isolated ...

A drawback in pancreatic islet transplantation is the large number of islets needed to obtain insulin independence in patients with diabetes. This most likely reflects extensive posttransplantation islet cell death and functional impairment of the remaining endocrine cells. We aimed to develop an experimental method to retrieve transplanted islets from the mouse liver, which would enable compar...

Insulin secretion has only exceptionally been investigated in pancreatic islets from healthy young children. It remains unclear whether those islets behave like adult islets despite substantial differences in cellular composition and higher β-cell replication rates. Islets were isolated from 5 infants/toddlers (11-36 month-old) and perifused to characterize their dynamics of insulin secretion w...

The purpose of this study was to characterize the trophic effect of pancreatic duct cells on the islets of Langerhans. Ductal epithelium and islets were isolated from hamster pancreata. In addition, duct-conditioned medium (DCM) was prepared from primary duct cultures that had been passaged twice to remove other cellular elements. Three experimental groups were then established: Group 1, 100 is...

Tight junctional fibrils were absent in freeze-fracture replicas of rat and human islets in situ, but were easily discerned in collagenase-isolated islets. Disruption of the pancreatic gland and its exposure to trypsin were each found to induce tight junction formation in rat islets. The amount of tight junctions between islet cells declined progressively during culture, but tight junctional st...

The reduction of functional β cell mass is a key feature of type 2 diabetes. Here, we studied metabolic functions and islet gene expression profiles of C57BL/6J mice with naturally occurring nicotinamide nucleotide transhydrogenase (NNT) deletion mutation, a widely used model of diet-induced obesity and diabetes. On high fat diet (HF), the mice developed obesity and hyperinsulinemia, while bloo...

BACKGROUND Vitamin D (vit D) affects glucose metabolism. Receptors of vitamin D have been identified in β cells and studies show that vitamin D deficiency reduces glucose-stimulated insulin secretion (GSIS). OBJECTIVES The aim of this study was to examine the effect of vitamin D on insulin release from isolated islets of rats. MATERIALS AND METHODS Islets were isolated from male Wistar rats...

OBJECTIVE To establish the role of the transcription factor Pax4 in pancreatic islet expansion and survival in response to physiological stress and its impact on glucose metabolism, we generated transgenic mice conditionally and selectively overexpressing Pax4 or a diabetes-linked mutant variant (Pax4R129W) in β-cells. RESEARCH DESIGN AND METHODS Glucose homeostasis and β-cell death and proli...

We have reported a high expression of IGF-I in pancreatic islet β-cells of transgenic mice under the metallothionein promoter. cDNA microarray analysis of the islets revealed that the expression of 82 genes was significantly altered compared to wild-type mice. Of these, 11β-hydroxysteroid dehydrogenase 1 (11β-HSD1), which is responsible for the conversion of inert cortisone (11-dehydrocorticost...

Heme oxygenase (HO)-1 expression was investigated in rat isolated pancreatic islets. Freshly isolated islets showed no evidence of HO-1 expression. After a 20-h culture, there was a small increase in HO-1 in control islets, and interleukin-1beta (IL-1beta) induced HO-1 expression above control levels. N(G)-monomethyl-L-arginine inhibited the IL-1beta-induced increase in HO-1. Sodium nitroprussi...