Insulin loaded hydrophobic nanoparticles were prepared by solvent diffusion followed by lyophilization. Nanoparticles were characterized for mean size by dynamic laser scattering and for shape by scanning electron microscopy. Insulin encapsulation efficiency, in vitro stability of nanoparticles in presence of proteolytic enzymes and in vitro release were determined by high pressure liquid chrom...

A mathematical model of the insulin-glucose feedback regulation in man is used to examine the effects of an oscillatory supply of insulin compared to a constant supply at the same average rate. We show that interactions between the oscillatory insulin supply and the receptor dynamics can be of minute significance only. It is possible, however, to interpret seemingly conflicting results of clini...

Novel glucose-sensitive systems for the release of insulin from poly(diethylaminoethyl methacrylate) (PDEAEM) micro-particles and nanoparticles decorated with glucose oxidase and catalase enzymes have been developed. The effect of polymer composition and loading conditions on the insulin loading efficiency and release was studied. The optimal conditions for loading insulin into PDEAEM micropart...

Inositol phospho-oligosaccharides (IPOs), which are released from liver membranes upon stimulation by insulin, mimic a wide spectrum of insulin effects in different cells, but not the stimulation of glucose transport. We investigated whether other insulin-sensitive tissues release glucose transport-stimulating IPOs and whether this is related to the human insulin receptor isoform-A or -B (HIR-A...

Bergsten, Peter. Glucose-induced pulsatile insulin release from single islets at stable and oscillatory cytoplasmic Ca21. Am. J. Physiol. 274 (Endocrinol. Metab. 37): E796– E800, 1998.—The cytoplasmic Ca21 concentration ([Ca]i) and insulin release were measured simultaneously in mouse pancreatic islets cultured overnight. [Ca]i was 105 nM and insulin release 3 pmol ·g21 ·s21 at 3 mM glucose. An...

BACKGROUND Polymorphisms in the potassium channel, voltage-gated, KQT-like subfamily, member 1 (KCNQ1) have recently been reported to associate with type 2 diabetes. The primary aim of the present study was to investigate the putative impact of these KCNQ1 polymorphisms (rs2283228, rs2237892, rs2237895, and rs2237897) on estimates of glucose stimulated insulin release. METHODOLOGY/PRINCIPAL F...

In this study, the synthesis, characterization and controlled release behavior of new Hollow Silica Nano particles (HSNPs) and Magnetic Silica Nano Particles (MSNPs) were studied. Magnetic Silica Nano particles (MSNPs), as drug delivery vehicles, were synthesized through the coating of Fe3O4 nano-crystals with silica layers. The HSNPs were obtained by removal of Fe3O4 templates with hydrochlori...

The active role played by beta-cell microfilamentous structures in the dynamics of insulin secretion was investigated by examining the influence of cytochalasin B upon various parameters of hormonal release by the isolated perfused rat pancreas. The view that the cytochalasin-induced changes in insulin release are due to a primary biophysical effect on microfilaments, rather than to an unrelate...

Nutrients such as glucose stimulate insulin release from pancreatic beta-cells through both ATP-sensitive K+ channel-independent and -dependent mechanisms, which are most likely interrelated. Although little is known of the molecular basis of ATP-sensitive K+ channel-independent insulinotropic nutrient actions, mediation by cytosolic long-chain acyl-CoA has been implicated. Because protein acyl...

Hereditary insulin-deficient diabetes mellitus occurs in certain sublines of nonobese Chinese hamsters. Several characteristics of this syndrome are similar to those seen in insulin-deficient human diabetics. Therefore, to characterize pancreatic islet function, dynamic insulin and glucagon release from normal and nonketotic diabetic hamster pancreases in response to glucose (300 mg/100 ml) and...