Search results for "Insulin secretion"
showing 10 items of 39 documents
The Impact of Amino Acids on Postprandial Glucose and Insulin Kinetics in Humans
2020
Different amino acids (AAs) may exert distinct effects on postprandial glucose and insulin concentrations. A quantitative comparison of the effects of AAs on glucose and insulin kinetics in humans is currently lacking. PubMed was queried to identify intervention studies reporting glucose and insulin concentrations after acute ingestion and/or intravenous infusion of AAs in healthy adults and those living with obesity and/or type 2 diabetes (T2DM). The systematic literature search identified 55 studies that examined the effects of l-leucine, l-isoleucine, l-alanine, l-glutamine, l-arginine, l-lysine, glycine, l-proline, l-phenylalanine, l-glutamate, branched-chain AAs (i.e., l-leucine, l-iso…
Reduction in insulin sensitivity and inadequate β-cell capacity to counteract the increase in insulin resistance in children with idiopathic growth h…
2014
Purpose: To evaluate the performance of various indexes of insulin sensitivity and secretion and to identify the most useful indicator of deterioration of glucose metabolism in a cohort of children with growth hormone (GH) deficiency (GHD) during GH treatment. Methods: In 73 GHD children (55 M, 18 F; mean age 10.5 years) at baseline and after 12 months of treatment, we evaluated a number of surrogate indexes of insulin secretion and sensitivity. In a subgroup of 11 children we also performed an euglycemic hyperinsulinemic clamp. Results: After 12 months, a significant increase in fasting glucose (p < 0.001) and HbA1c levels (p < 0.001) was documented, despite all children remained with a no…
One-hour post-load plasma glucose level is associated with a worse metabolic profile in children with GH deficiency
2017
Purpose: In children, the plasma glucose value at 1 h (1hPG) during OGTT higher than 132.5 mg/dl is a predictor of alterations in glucose metabolism. We aimed to metabolically characterize GHD children according to 1hPG levels. Methods: Fifty-one GHD children (35 M, 16 F; mean age 8.6 years), grouped according to 1hPG, were evaluated at diagnosis and after 12 months of GH treatment (GHT) and compared with 50 matched controls at baseline. Auxological parameters, insulin-like growth factor-1 (IGF-1), glucose and insulin during OGTT, lipid profile, the oral disposition index (DIo), the homeostasis model assessment estimate of insulin resistance (Homa-IR), and the insulin sensitivity index (ISI…
Comparison of the Effects of Glibenclamide on Metabolic Parameters, GLUT1 Expression, and Liver Injury in Rats With Severe and Mild Streptozotocin-In…
2012
Background and Objective. Glucose transport via GLUT1 protein could be one of additional mechanisms of the antidiabetic action of sulfonylureas. Here, the GLUT1 gene and the protein expression was studied in rats in the course of severe and mild streptozotocin-induced diabetes mellitus and under glibenclamide treatment. Material and Methods. Severe and mild diabetes mellitus was induced using different streptozotocin doses and standard or high fat chow. Rats were treated with glibenclamide (2 mg/kg daily, per os for 6 weeks). The therapeutic effect of glibenclamide was monitored by measuring several metabolic parameters. The GLUT1 mRNA and the protein expression in the kidneys, heart, and l…
Improved insulin sensitivity and secretion in prediabetic patients with adrenal insufficiency on dual-release hydrocortisone treatment: a 36-month re…
2018
OBJECTIVE Dual-release hydrocortisone (DR-HC) provides physiological cortisol exposure, leading to an improvement of anthropometric and metabolic parameters. The aim of the study was to evaluate the effects of DR-HC on insulin secretion and sensitivity and cardiometabolic risk, indirectly expressed by the visceral adiposity index (VAI). DESIGN AND PATIENTS Retrospective analysis of 49 patients, 13 with primary and 36 with secondary adrenal insufficiency (AI), respectively, on conventional glucocorticoid treatment at baseline and switched to DR-HC for 36 months. Overall, 24 patients had AI-pre-diabetes (impaired fasting glucose, impaired glucose tolerance and the combination), and 25 had AI-…
Dynamics of Ca2+ and guanosine 5'-[gamma-thio]triphosphate action on insulin secretion from alpha-toxin-permeabilized HIT-T15 cells.
1994
The time course of Ca2+ and GTP-analogue effects on insulin secretion was investigated in HIT-T15 cells permeabilized with Staphylococcus alpha-toxin. These cells responded to Ca2+ in the range 0.1-10 microM and could be used in a dynamic perifusion system because of the minimal run-down of the secretory response. High Ca2+ (10 microM) elicited a monophasic ATP-dependent stimulation of insulin secretion that reached a peak within 5 min (approximately 20-fold increase) and rapidly decreased during the subsequent 15 min to a plateau remaining above basal rates (0.1 microM Ca2+). The decrease in Ca(2+)-induced insulin secretion with time could not be attributed to decreased capacity to respond…
Soluble N-ethylmaleimide-sensitive-factor attachment protein and N-ethylmaleimide-insensitive factors are required for Ca2+-stimulated exocytosis of …
1996
Ca2+ stimulates exocytosis in permeabilized insulin-secreting cells. To investigate the putative cytosolic components involved in the Ca2+ response, HIT-T15 cells (a pancreatic B-cell line) were permeabilized with streptolysin-O, a procedure that allows rapid exchange of soluble components including macromolecules. We found that in this cell preparation the secretory response to Ca2+ but not to guanosine 5'-[gamma-thio]triphosphate was lost as a function of time and could be restored by rat brain cytosol in a concentration-dependent manner. Reconstitutive activity of rat brain cytosol was found in a high-molecular-mass heat-labile partially N-ethylmaleimide(NEM)-sensitive fraction. The NEM-…
Determination of heavy metal content and lipid profiles in mussel extracts from two sites on the moroccan atlantic coast and evaluation of their biol…
2012
Mussels may concentrate pollutants, with possibly significant side effects on human health. Therefore, mussels (Mytilus galloprovincialis) from two sites of the Moroccan Atlantic coast (Jorf Lasfar [JL], an industrial site, and Oualidia [OL], a vegetable-growing area), were subjected to biochemical analyses to quantify the presence of heavy metals (Cd, Cr, and Pb) and to establish the lipid profile: fatty acid, cholesterol, oxysterol, phytosterol and phospholipid content. In addition, mussel lipid extracts known to accumulate numerous toxic components were tested on murine pancreatic β-cells (MIN6), and their biological activities were measured with various flow cytometric and biochemical m…
SNAP-25a and -25b isoforms are both expressed in insulin-secreting cells and can function in insulin secretion
1999
The tSNARE (the target-membrane soluble NSF-attachment protein receptor, where NSF is N-ethylmaleimide-sensitive fusion protein) synaptosomal-associated protein of 25 kDa (SNAP-25) is expressed in pancreatic B-cells and its cleavage by botulinum neurotoxin E (BoNT/E) abolishes stimulated secretion of insulin. In the nervous system, two SNAP-25 isoforms (a and b) have been described that are produced by alternative splicing. Here it is shown, using reverse transcriptase PCR, that messages for both SNAP-25 isoforms are expressed in primary pancreatic B and non-B cells as well as in insulin-secreting cell lines. After transfection, both isoforms can be detected at the plasma membrane as well a…
Defective insulin secretory response to intravenous glucose in C57Bl/6J compared to C57Bl/6N mice
2014
Objective: The C57Bl/6J (Bl/6J) mouse is the most widely used strain in metabolic research. This strain carries a mutation in nicotinamide nucleotide transhydrogenase (Nnt), a mitochondrial enzyme involved in NADPH production, which has been suggested to lead to glucose intolerance and beta-cell dysfunction. However, recent reports comparing Bl/6J to Bl/6N (carrying the wild-type Nnt allele) under normal diet have led to conflicting results using glucose tolerance tests. Thus, we assessed glucose-stimulated insulin secretion (GSIS), insulin sensitivity, clearance and central glucose-induced insulin secretion in Bl/6J and N mice using gold-standard methodologies. Methods: GSIS was measured u…