Biomaterial Database

Aromatic-L-amino-acid decarboxylase activity in mouse pancreatic islets. 1986

P Lindström

Aromatic-L-amino-acid decarboxylase activity has been measured in intact or homogenised pancreatic islets of ob/ob mice (Umeå ob/ob). The method used involves the trapping and measuring of the 14CO2 released from L-[1-14C]dihydroxyphenylalanine (L-dopa). Islets showed a decarboxylase activity which was dependent on pyridoxal phosphate and inhibitable by 0.1 mM benserazide or 0.1 mM alpha-monofluoromethyldopa. Maximum activity in intact islets was about 330 mmol/kg dry islet per h with an apparent Km of 3.3 mM. Islet homogenates had a Vmax of about 120 mmol/kg per h with a Km of 0.3 mM. L-5-Hydroxytryptophan, m-tyrosine and o-tyrosine interfered with the decarboxylation of L-dopa in a way that suggested a high activity also towards those substrates. L-Phenylalanine, L-tyrosine and D-glucose had no effect. At 0.05 mM L-dopa islet homogenates showed a much higher activity than homogenates of liver, kidney, or spleen. Islet uptake of L-[3H]dopa was well in excess of the decarboxylation rate and thus probably not rate-limiting. It is concluded that mouse pancreatic islets have a high activity of aromatic-L-amino-acid decarboxylase. This is in accordance with previous suggestions of a stimulatory effect of this enzyme on insulin secretion.

UI	MeSH Term	Description	Entries
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
D007980	Levodopa	The naturally occurring form of DIHYDROXYPHENYLALANINE and the immediate precursor of DOPAMINE. Unlike dopamine itself, it can be taken orally and crosses the blood-brain barrier. It is rapidly taken up by dopaminergic neurons and converted to DOPAMINE. It is used for the treatment of PARKINSONIAN DISORDERS and is usually given with agents that inhibit its conversion to dopamine outside of the central nervous system.	L-Dopa,3-Hydroxy-L-tyrosine,Dopaflex,Dopar,L-3,4-Dihydroxyphenylalanine,Larodopa,Levopa,3 Hydroxy L tyrosine,L 3,4 Dihydroxyphenylalanine,L Dopa
D008820	Mice, Obese	Mutant mice exhibiting a marked obesity coupled with overeating, hyperglycemia, hyperinsulinemia, marked insulin resistance, and infertility when in a homozygous state. They may be inbred or hybrid.	Hyperglycemic Mice,Obese Mice,Mouse, Hyperglycemic,Mouse, Obese,Hyperglycemic Mouse,Mice, Hyperglycemic,Obese Mouse
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
D001142	Aromatic-L-Amino-Acid Decarboxylases	An enzyme group with broad specificity. The enzymes decarboxylate a range of aromatic amino acids including dihydroxyphenylalanine (DOPA DECARBOXYLASE); TRYPTOPHAN; and HYDROXYTRYPTOPHAN.	Amino Acid Decarboxylases, Aromatic,Aromatic Amino Acid Decarboxylase,Aromatic Amino Acid Decarboxylases,5-HTPase,5-Hydroxytryptophan Decarboxylase,Aromatic-L-Amino-Acid Decarboxylase,Hydroxytryptophan Decarboxylase,Tryptophan Decarboxylase,5 HTPase,5 Hydroxytryptophan Decarboxylase,Aromatic L Amino Acid Decarboxylase,Aromatic L Amino Acid Decarboxylases,Decarboxylase, 5-Hydroxytryptophan,Decarboxylase, Aromatic-L-Amino-Acid,Decarboxylase, Hydroxytryptophan,Decarboxylase, Tryptophan,Decarboxylases, Aromatic-L-Amino-Acid
D051379	Mice	The common name for the genus Mus.	Mice, House,Mus,Mus musculus,Mice, Laboratory,Mouse,Mouse, House,Mouse, Laboratory,Mouse, Swiss,Mus domesticus,Mus musculus domesticus,Swiss Mice,House Mice,House Mouse,Laboratory Mice,Laboratory Mouse,Mice, Swiss,Swiss Mouse,domesticus, Mus musculus
D065105	Aromatic Amino Acid Decarboxylase Inhibitors	Compounds and drugs that block or inhibit the enzymatic action of AROMATIC AMINO ACID DECARBOXYLASES. Pharmaceutical agents in this category are used in conjunction with LEVODOPA in order to slow its metabolism.	Aromatic-L-Amino-Acid Decarboxylase Inhibitors,DOPA Decarboxylase Inhibitors,Dihydroxyphenylalanine Decarboxylase Inhibitors,Aromatic L Amino Acid Decarboxylase Inhibitors,Decarboxylase Inhibitors, Aromatic-L-Amino-Acid,Decarboxylase Inhibitors, DOPA,Decarboxylase Inhibitors, Dihydroxyphenylalanine,Inhibitors, Aromatic-L-Amino-Acid Decarboxylase,Inhibitors, DOPA Decarboxylase,Inhibitors, Dihydroxyphenylalanine Decarboxylase
D066298	In Vitro Techniques	Methods to study reactions or processes taking place in an artificial environment outside the living organism.	In Vitro Test,In Vitro Testing,In Vitro Tests,In Vitro as Topic,In Vitro,In Vitro Technique,In Vitro Testings,Technique, In Vitro,Techniques, In Vitro,Test, In Vitro,Testing, In Vitro,Testings, In Vitro,Tests, In Vitro,Vitro Testing, In