Kinetics of (45)Ca efflux and insulin release were studied in collagenase-isolated rat islets during 2-h perifusions with calcium-depleted (0.05 mM) bicarbonate-phosphate buffer containing 2.2 mM glucose. Addition of glucose (16.7 mM) suppressed (45)Ca efflux by 30%. Removal of glucose caused an "off response" of insulin release. The perifusion of a normal concentration of Ca (2.3 mM) greatly s...

Takehiro, Mihoko, Shimpei Fujimoto, Makiko Shimodahira, Dai Shimono, Eri Mukai, Koichiro Nabe, Razvan Gheorghe Radu, Rieko Kominato, Yo Aramaki, Yutaka Seino, and Yuichiro Yamada. Chronic exposure to -hydroxybutyrate inhibits glucoseinduced insulin release from pancreatic islets by decreasing NADH contents. Am J Physiol Endocrinol Metab 288: E372–E380, 2005. First published October 12, 2004; do...

Early insulin response to rapid intravenous injection of glucose was studied in 7 cases of cystic fibrosis aged 8 months to 9 1/2 years. Plasma insulin was measured with a radioimmunological method. Blood glucose values were determined and the glucose disappearance rate (kG) calculated. In all children except the youngest one the early insulin response values were low compared with normal child...

This study proposes a new concept of pH-sensitive poly(lactide-co-glycolide) (PLGA) nanoparticle composite microcapsules for oral delivery of insulin. Firstly, insulin-sodium oleate complex was prepared by the hydrophobic ion pairing method and then encapsulated into PLGA nanoparticles by the emulsion solvent diffusion method. In order to reduce the burst release of insulin from PLGA nanopartic...

Because insulin acutely enhances the function of dopamine transporters, the tyrosine kinase receptors activated by this hormone may modulate transporter-dependent neurochemical and behavioral effects of psychoactive drugs. In this respect, we examined the effects of insulin on exocytotic monoamine release and the efficacy of the monoamine transporter blocker cocaine in rat nucleus accumbens. Wh...

The aim of this study was to design a controlled release vehicle for insulin to preserve its stability and biological activity during fabrication and release. A modified, double emulsion, solvent evaporation, technique using homogenisation force optimised entrapment efficiency of insulin into biodegradable nanoparticles (NP) prepared from poly (DL-lactic-co-glycolic acid) (PLGA) and its PEGylat...

Pancreatic beta-cells and skeletal muscle act in a synergic way in the control of systemic glucose homeostasis. Several pyruvate-dependent and -independent shuttles enhance tricarboxylic acid cycle intermediate (TACI) anaplerosis and increase beta-cell ATP:ADP ratio, triggering insulin exocytotic mechanisms. In addition, mitochondrial TACI cataplerosis gives rise to the so-called metabolic coup...

Insulin concentrations in humans continuously change and typically increase only when glucose also increases such as with eating. In this setting, it is not known whether the severity of hepatic and extrahepatic insulin resistance is comparable and whether the ability of glucose to regulate its own uptake and release is defective in non-insulin-dependent diabetes mellitus (NIDDM). To address th...

It is intriguing that the kinetics of glucose-stimulated insulin secretion from the in situ perfused pancreas differ between the rat and the mouse. Here we confirm that insulin release in the rat is clearly biphasic, whereas in the mouse glucose essentially elicits a transient monophasic insulin release. Glucose-derived glutamate has been suggested to participate in the full development of the ...

Secreted ligands of the insulin family promote cell growth and maintain sugar homeostasis. Insulin release is tightly regulated in response to dietary conditions, but how insulin-producing cells (IPCs) coordinate their responses to distinct nutrient signals is unclear. Here we show that regulation of insulin secretion in Drosophila larvae has been segregated into distinct branches-whereas amino...