Mice were subjected to gastrectomy (GX) or sham operation (controls). Four to six weeks later the pancreatic islets were isolated and analysed for cAMP or alternatively incubated in a Krebs-Ringer based medium in an effort to study insulin secretion and cAMP accumulation in response to glucose or the adenylate cyclase activator forskolin. Freshly isolated islets from GX mice had higher cAMP con...

Expression of immune modulating mediators in human Islets of Langerhans could have important implications for development of autoimmunity in type 1 diabetes and influence the outcome of clinical islet transplantation. Islets obtained from five donors were analyzed at various times after isolation using cDNA array technology. The Atlas Human Cytokine/Receptor and Hematology/Immunology nylon memb...

OBJECTIVE Ganoderma Lucidum (G. Lucidum) has been suggested to increase serum insulin level. This study was undertaken to investigate its direct effect on the islets of Langerhans. MATERIAL AND METHODS Male albino Wistar rats were anesthetized and the islets were isolated after digestion of the pancreas with collagenase. The islets were incubated for 60 min in Krebs bicarbonate buffer contain...

We describe a method for the preparation of viable islets from the pancreas of normal 8-week-old female Syrian golden hamster, based on the injection of the pancreatic duct with collagenase and on mechanical dissociation which liberates islets that maintain their normal morphological appearance and physiologic function. In a series of 11 animals, we examined the dose response of intraductal col...

We generated transgenic mice carrying the mouse type 2 nitric-oxide synthase (NOS2) cDNA under the control of the insulin promoter. Western and immunohistochemical analyses revealed that NOS2 was expressed abundantly in transgenic islets but not in control islets. When islets were isolated and cultured, high levels of nitrite were released from the transgenic islets. In transgenic mice, the bet...

Objective: Adrenaline inhibits insulin secretion through activation of a2-adrenoceptors (ARs). These receptors are linked to pertussis toxin-sensitive G proteins. Agonist binding leads to inhibition of adenylyl cyclase, inhibition of Ca2þ channels and activation of Kþ channels. Recently, three distinct subtypes of a2-AR were described, a2A-AR, a2B-AR and a2C-AR. At present, it is unknown which ...

Strategies for restoring beta-cell function in diabetic patients would be greatly aided by the ability to target genes, proteins, or small molecules specifically to these cells. Furthermore, the ability to direct imaging agents specifically to beta-cells would facilitate diagnosis and monitoring of disease progression. To isolate ligands that can home to beta-cells in vivo, we have panned a ran...

Isolated human pancreatic islets converted [3H8]arachidonate to compounds with the high-performance liquid-chromatographic mobility of cyclooxygenase products, including prostaglandin E2 (PGE2), PGF2 alpha, and the lipoxygenase product 12-HETE. Human islet synthesis of PGE2, PGF2 alpha, and 12-HETE from endogenous arachidonate was demonstrated with stable isotope dilution-gas chromatographic-ne...

We have studied the effects of first and second generation sulphonylureas on the release of insulin and neuropeptide tyrosine (NPY) from hamster insulinoma tumour (HIT T15) cells and isolated rat islets. In the presence of 5.5 mmol/l glucose all sulphonylureas stimulated insulin release from the HIT cells (P<0.01 ANOVA, n> or =4) but only glibenclamide (GLIB, 10 micromol/l) stimulated the relea...

We have shown that oxidative stress is a mechanism of free fatty acid (FFA)-induced β-cell dysfunction. Unsaturated fatty acids in membranes, including plasma and mitochondrial membranes, are substrates for lipid peroxidation, and lipid peroxidation products are known to cause impaired insulin secretion. Therefore, we hypothesized that mice overexpressing glutathione peroxidase-4 (GPx4), an enz...