Biomaterial Database

Regulation of insulin biosynthesis in carp islets (Cyprinus carpio). 1981

A Huth, and T A Rapoport

The biosynthesis of proinsulin was measured by the incorporation of radiolabelled leucine and phenylalanine into carp islet protein. Even in the absence of glucose or amino acids in the medium the share of proinsulin in the total protein biosynthesis amounted to 40% of the total incorporated [3H]-leucine during 2 h of incubation. Glucose increased the rate of total protein biosynthesis in carp islets by approximately 20%, but no preferential increase of proinsulin synthesis occurred in the presence of glucose. Furthermore leucine did not increase [3H]-phenylalanine incorporation into proinsulin. Cyproheptadine, a specific inhibitor of proinsulin biosynthesis in mammals, did not inhibit in carp islets. The total protein synthesis was strongly dependent on the temperature. The share of proinsulin synthesis decreased from 40% at 17 degrees C to 20% at 4 degrees C. Even more drastically, the conversion of proinsulin to insulin became slower at lower temperatures and was undetectable at 4 degrees C. The results indicate that in contrast to mammals, in islets of the poikilotherm carp, metabolic substrates may play a less important role that the temperature in the regulation of insulin 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.
D007930	Leucine	An essential branched-chain amino acid important for hemoglobin formation.	L-Leucine,Leucine, L-Isomer,L-Isomer Leucine,Leucine, L Isomer
D011384	Proinsulin	A pancreatic polypeptide of about 110 amino acids, depending on the species, that is the precursor of insulin. Proinsulin, produced by the PANCREATIC BETA CELLS, is comprised sequentially of the N-terminal B-chain, the proteolytically removable connecting C-peptide, and the C-terminal A-chain. It also contains three disulfide bonds, two between A-chain and B-chain. After cleavage at two locations, insulin and C-peptide are the secreted products. Intact proinsulin with low bioactivity also is secreted in small amounts.
D002347	Carps	Common name for a number of different species of fish in the family Cyprinidae. This includes, among others, the common carp, crucian carp, grass carp, and silver carp.	Carassius carassius,Crucian Carp,Cyprinus,Grass Carp,Carp,Ctenopharyngodon idellus,Cyprinus carpio,Hypophthalmichthys molitrix,Koi Carp,Silver Carp,Carp, Crucian,Carp, Grass,Carp, Koi,Carp, Silver,Carps, Crucian,Carps, Grass,Carps, Silver,Crucian Carps,Grass Carps,Silver Carps
D003533	Cyproheptadine	A serotonin antagonist and a histamine H1 blocker used as antipruritic, appetite stimulant, antiallergic, and for the post-gastrectomy dumping syndrome, etc.	Antergan,Dihexazin,Periactin,Peritol,Viternum
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
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
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