Biomaterial Database

Regulation of energy metabolism in pancreatic islets by glucose and tolbutamide. 1986

U Panten, and B J Zünkler, and S Scheit, and K Kirchhoff, and S Lenzen

The kinetics of insulin secretion and oxygen uptake in response to D-glucose and tolbutamide were compared in mouse pancreatic islets. In addition, the role of decreased ATP as a driving force for secretagogue-induced oxygen consumption was examined. D-glucose (10-30 mmol/l) triggered a biphasic insulin release which always coincided with a monophasic increase in islet oxygen uptake. In the presence of D-glucose (5-30 mmol/l), tolbutamide (3-500 mumol/l) consistently elicited an initial peak of insulin secretion which was followed by a continued decline. Tolbutamide-induced secretory profiles were accompanied by similar respiratory profiles. Oxygen consumption per ng of insulin released during the test phase was higher after elevation of the glucose concentration than after addition of tolbutamide. In conjunction with 5 or 10 mmol/l D-glucose, but not with 15 or 30 mmol/l D-glucose, tolbutamide (30-100 mumol/l) lowered islet ATP content significantly (p less than 0.02). Phosphocreatine was not found in isolated islets, although they contained substantial creatine kinase activity. It is concluded that the driving force for tolbutamide-induced oxygen uptake is a decrease in the phosphorylation potential caused by the work load imposed by stimulation of the secretion process. However, a major proportion of the respiratory response to glucose also results from enhancement of biosynthesis.

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
D007700	Kinetics	The rate dynamics in chemical or physical systems.
D008297	Male		Males
D010101	Oxygen Consumption	The rate at which oxygen is used by a tissue; microliters of oxygen STPD used per milligram of tissue per hour; the rate at which oxygen enters the blood from alveolar gas, equal in the steady state to the consumption of oxygen by tissue metabolism throughout the body. (Stedman, 25th ed, p346)	Consumption, Oxygen,Consumptions, Oxygen,Oxygen Consumptions
D004734	Energy Metabolism	The chemical reactions involved in the production and utilization of various forms of energy in cells.	Bioenergetics,Energy Expenditure,Bioenergetic,Energy Expenditures,Energy Metabolisms,Expenditure, Energy,Expenditures, Energy,Metabolism, Energy,Metabolisms, Energy
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
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
D014044	Tolbutamide	A sulphonylurea hypoglycemic agent with actions and uses similar to those of CHLORPROPAMIDE. (From Martindale, The Extra Pharmacopoeia, 30th ed, p290)	Apo-Tolbutamide,Artosin,Diabetol,Diaval,Dolipol,Orabet,Orinase,Rastinon,Tolbutamid R.A.N.