Glucose transport, phosphorylation, and utilization in isolated porcine pancreatic islets. 1995

A M Rabuazzo, and A M Davalli, and M Buscema, and C Socci, and V Caltabiano, and A E Pontiroli, and V Di Carlo, and G Pozza, and R Vigneri, and F Purrello
Institute of Internal Medicine, Metabolism, and Endocrinology, University of Catania Medical School, Italy.

Porcine islets have been proposed as a donor source for human transplantation, mainly because of both structural and biological similarities of porcine and human insulin. However, the in vitro function of these islets is poorly characterized. In the present study, we first examined insulin release in response to glucose in static incubation experiments. Increasing glucose concentrations up to 8.3 mmol/L stimulated insulin release; however, this elevation was only twofold, and a paradoxical decline was observed at glucose concentrations higher than 8.3 mmol/L. In cultured porcine islets, a greater insulin secretion may be elicited by agents that increase intracellular cyclic adenosine monophosphate (cAMP) levels. To investigate the possible reasons for the porcine islet low response to glucose in vitro, we then evaluated in parallel experiments glucose transport, phosphorylation, and utilization. Glucose transport studies (using 3-O-methyl glucose uptake at 15 degrees C for 15 seconds) indicated the presence of both a high-affinity (Km, 1.2 +/- 0.6 mmol/L) and a low-affinity (Km, 11.8 +/- 1.9 nmol/L, n = 5) component. Glucose phosphorylation, evaluated by measuring the rate of glucose-6-phosphate formation in a fluorimetric assay, indicated that glucokinase activity had a maximum (Vmax) of 7.97 +/- 0.94 nmol/microgram DNA/h and a Km of 8.3 +/- 0.9 mmol/L (mean +/- SE, n = 8).(ABSTRACT TRUNCATED AT 250 WORDS)

UI MeSH Term Description Entries
D007328 Insulin A 51-amino acid pancreatic hormone that plays a major role in the regulation of glucose metabolism, directly by suppressing endogenous glucose production (GLYCOGENOLYSIS; GLUCONEOGENESIS) and indirectly by suppressing GLUCAGON secretion and LIPOLYSIS. Native insulin is a globular protein comprised of a zinc-coordinated hexamer. Each insulin monomer containing two chains, A (21 residues) and B (30 residues), linked by two disulfide bonds. Insulin is used as a drug to control insulin-dependent diabetes mellitus (DIABETES MELLITUS, TYPE 1). Iletin,Insulin A Chain,Insulin B Chain,Insulin, Regular,Novolin,Sodium Insulin,Soluble Insulin,Chain, Insulin B,Insulin, Sodium,Insulin, Soluble,Regular Insulin
D007515 Islets of Langerhans Irregular microscopic structures consisting of cords of endocrine cells that are scattered throughout the PANCREAS among the exocrine acini. Each islet is surrounded by connective tissue fibers and penetrated by a network of capillaries. There are four major cell types. The most abundant beta cells (50-80%) secrete INSULIN. Alpha cells (5-20%) secrete GLUCAGON. PP cells (10-35%) secrete PANCREATIC POLYPEPTIDE. Delta cells (~5%) secrete SOMATOSTATIN. Islands of Langerhans,Islet Cells,Nesidioblasts,Pancreas, Endocrine,Pancreatic Islets,Cell, Islet,Cells, Islet,Endocrine Pancreas,Islet Cell,Islet, Pancreatic,Islets, Pancreatic,Langerhans Islands,Langerhans Islets,Nesidioblast,Pancreatic Islet
D009004 Monosaccharide Transport Proteins A large group of membrane transport proteins that shuttle MONOSACCHARIDES across CELL MEMBRANES. Hexose Transport Proteins,Band 4.5 Preactin,Erythrocyte Band 4.5 Protein,Glucose Transport-Inducing Protein,Hexose Transporter,4.5 Preactin, Band,Glucose Transport Inducing Protein,Preactin, Band 4.5,Proteins, Monosaccharide Transport,Transport Proteins, Hexose,Transport Proteins, Monosaccharide,Transport-Inducing Protein, Glucose
D010766 Phosphorylation The introduction of a phosphoryl group into a compound through the formation of an ester bond between the compound and a phosphorus moiety. Phosphorylations
D003470 Culture Media Any liquid or solid preparation made specifically for the growth, storage, or transport of microorganisms or other types of cells. The variety of media that exist allow for the culturing of specific microorganisms and cell types, such as differential media, selective media, test media, and defined media. Solid media consist of liquid media that have been solidified with an agent such as AGAR or GELATIN. Media, Culture
D005947 Glucose A primary source of energy for living organisms. It is naturally occurring and is found in fruits and other parts of plants in its free state. It is used therapeutically in fluid and nutrient replacement. Dextrose,Anhydrous Dextrose,D-Glucose,Glucose Monohydrate,Glucose, (DL)-Isomer,Glucose, (alpha-D)-Isomer,Glucose, (beta-D)-Isomer,D Glucose,Dextrose, Anhydrous,Monohydrate, Glucose
D000078790 Insulin Secretion Production and release of insulin from PANCREATIC BETA CELLS that primarily occurs in response to elevated BLOOD GLUCOSE levels. Secretion, Insulin
D000242 Cyclic AMP An adenine nucleotide containing one phosphate group which is esterified to both the 3'- and 5'-positions of the sugar moiety. It is a second messenger and a key intracellular regulator, functioning as a mediator of activity for a number of hormones, including epinephrine, glucagon, and ACTH. Adenosine Cyclic 3',5'-Monophosphate,Adenosine Cyclic 3,5 Monophosphate,Adenosine Cyclic Monophosphate,Adenosine Cyclic-3',5'-Monophosphate,Cyclic AMP, (R)-Isomer,Cyclic AMP, Disodium Salt,Cyclic AMP, Monoammonium Salt,Cyclic AMP, Monopotassium Salt,Cyclic AMP, Monosodium Salt,Cyclic AMP, Sodium Salt,3',5'-Monophosphate, Adenosine Cyclic,AMP, Cyclic,Adenosine Cyclic 3',5' Monophosphate,Cyclic 3',5'-Monophosphate, Adenosine,Cyclic Monophosphate, Adenosine,Cyclic-3',5'-Monophosphate, Adenosine,Monophosphate, Adenosine Cyclic
D000818 Animals Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA. Animal,Metazoa,Animalia
D001692 Biological Transport The movement of materials (including biochemical substances and drugs) through a biological system at the cellular level. The transport can be across cell membranes and epithelial layers. It also can occur within intracellular compartments and extracellular compartments. Transport, Biological,Biologic Transport,Transport, Biologic

Related Publications

A M Rabuazzo, and A M Davalli, and M Buscema, and C Socci, and V Caltabiano, and A E Pontiroli, and V Di Carlo, and G Pozza, and R Vigneri, and F Purrello
April 1968, The Biochemical journal,
A M Rabuazzo, and A M Davalli, and M Buscema, and C Socci, and V Caltabiano, and A E Pontiroli, and V Di Carlo, and G Pozza, and R Vigneri, and F Purrello
February 1990, Biochimica et biophysica acta,
A M Rabuazzo, and A M Davalli, and M Buscema, and C Socci, and V Caltabiano, and A E Pontiroli, and V Di Carlo, and G Pozza, and R Vigneri, and F Purrello
February 1985, Molecular and cellular biochemistry,
A M Rabuazzo, and A M Davalli, and M Buscema, and C Socci, and V Caltabiano, and A E Pontiroli, and V Di Carlo, and G Pozza, and R Vigneri, and F Purrello
February 1994, Transplantation,
A M Rabuazzo, and A M Davalli, and M Buscema, and C Socci, and V Caltabiano, and A E Pontiroli, and V Di Carlo, and G Pozza, and R Vigneri, and F Purrello
December 1994, Transplantation proceedings,
A M Rabuazzo, and A M Davalli, and M Buscema, and C Socci, and V Caltabiano, and A E Pontiroli, and V Di Carlo, and G Pozza, and R Vigneri, and F Purrello
April 1981, Biochemical and biophysical research communications,
A M Rabuazzo, and A M Davalli, and M Buscema, and C Socci, and V Caltabiano, and A E Pontiroli, and V Di Carlo, and G Pozza, and R Vigneri, and F Purrello
June 1984, Archives of biochemistry and biophysics,
A M Rabuazzo, and A M Davalli, and M Buscema, and C Socci, and V Caltabiano, and A E Pontiroli, and V Di Carlo, and G Pozza, and R Vigneri, and F Purrello
September 1985, Life sciences,
A M Rabuazzo, and A M Davalli, and M Buscema, and C Socci, and V Caltabiano, and A E Pontiroli, and V Di Carlo, and G Pozza, and R Vigneri, and F Purrello
December 1983, The Journal of biological chemistry,
A M Rabuazzo, and A M Davalli, and M Buscema, and C Socci, and V Caltabiano, and A E Pontiroli, and V Di Carlo, and G Pozza, and R Vigneri, and F Purrello
August 2010, Journal of molecular endocrinology,
Copied contents to your clipboard!