Biomaterial Database

Thyroid status regulates particulate but not soluble TRH-degrading pyroglutamate aminopeptidase activity in the rat liver. 1990

R Scharfmann, and J C Ebiou, and J L Morgat, and S Aratan-Spire

INSERM U 30, Hôpital des Enfants Malades, Paris, France.

Rat liver contains two topologically different TRH-degrading pyroglutamate aminopeptidases. The particulate pyroglutamate aminopeptidase, unlike the soluble one, was highly specific for TRH and shared many physico-chemical properties with serum thyroliberinase, which is controlled by thyroid hormones. Both enzymes convert pGlu His Pro NH2 into His Pro NH2; the latter may be cyclized to cyclo His Pro known to possess several biological activities and specific binding sites in liver. The aim of the present study was to determine the effects of thyroid status on the particulate and soluble enzymes activity and gain more insight into their biological role. The regulatory pathway for the particulate pyroglutamate aminopeptidase was found similar to that of serum thyroliberinase: their specific activities decrease in hypothyroid rats and increase in hyperthyroid rats, whereas that of soluble enzyme remains unchanged. We postulate that the particulate pyroglutamate aminopeptidase may be a determining factor in the concentrations of TRH and/or cyclo His Pro reaching liver cells and a possible source for serum thyroliberinase. Taken together, these data suggest that this "converting enzyme" acts as a physiological regulator.

UI	MeSH Term	Description	Entries
D006980	Hyperthyroidism	Hypersecretion of THYROID HORMONES from the THYROID GLAND. Elevated levels of thyroid hormones increase BASAL METABOLIC RATE.	Hyperthyroid,Primary Hyperthyroidism,Hyperthyroidism, Primary,Hyperthyroids
D007037	Hypothyroidism	A syndrome that results from abnormally low secretion of THYROID HORMONES from the THYROID GLAND, leading to a decrease in BASAL METABOLIC RATE. In its most severe form, there is accumulation of MUCOPOLYSACCHARIDES in the SKIN and EDEMA, known as MYXEDEMA. It may be primary or secondary due to other pituitary disease, or hypothalamic dysfunction.	Central Hypothyroidism,Primary Hypothyroidism,Secondary Hypothyroidism,TSH Deficiency,Thyroid-Stimulating Hormone Deficiency,Central Hypothyroidisms,Deficiency, TSH,Deficiency, Thyroid-Stimulating Hormone,Hormone Deficiency, Thyroid-Stimulating,Hypothyroidism, Central,Hypothyroidism, Primary,Hypothyroidism, Secondary,Hypothyroidisms,Primary Hypothyroidisms,Secondary Hypothyroidisms,TSH Deficiencies,Thyroid Stimulating Hormone Deficiency,Thyroid-Stimulating Hormone Deficiencies
D007531	Isoflurophate	A di-isopropyl-fluorophosphate which is an irreversible cholinesterase inhibitor used to investigate the NERVOUS SYSTEM.	DFP,Diisopropylfluorophosphate,Fluostigmine,Bis(1-methylethyl) Phosphorofluoridate,Di-isopropylphosphorofluoridate,Diisopropylphosphofluoridate,Dyflos,Floropryl,Fluorostigmine,Di isopropylphosphorofluoridate
D007700	Kinetics	The rate dynamics in chemical or physical systems.
D008099	Liver	A large lobed glandular organ in the abdomen of vertebrates that is responsible for detoxification, metabolism, synthesis and storage of various substances.	Livers
D008297	Male		Males
D011441	Propylthiouracil	A thiourea antithyroid agent. Propythiouracil inhibits the synthesis of thyroxine and inhibits the peripheral conversion of throxine to tri-iodothyronine. It is used in the treatment of hyperthyroidism. (From Martindale, The Extra Pharmacopeoia, 30th ed, p534)	6-Propyl-2-Thiouracil,6 Propyl 2 Thiouracil
D011751	Pyroglutamyl-Peptidase I	An enzyme that catalyzes the release of a N-terminal pyroglutamyl group from a polypeptide provided the next residue is not proline. It is inhibited by thiol-blocking reagents and occurs in mammalian tissues, microorganisms, and plants. (From Enzyme Nomenclature, 1992) EC 3.4.19.3.	5-Oxoprolyl-Peptidase,Pyroglutamate Aminopeptidase,Pyrrolidonecarboxylate Peptidase,Pyrrolidonyl Peptidase,Pyroglutamyl-Peptide Hydrolase,5 Oxoprolyl Peptidase,Aminopeptidase, Pyroglutamate,Peptidase, Pyrrolidonecarboxylate,Peptidase, Pyrrolidonyl,Pyroglutamyl Peptidase I,Pyroglutamyl Peptide Hydrolase
D011761	Pyrrolidonecarboxylic Acid	A cyclized derivative of L-GLUTAMIC ACID. Elevated blood levels may be associated with problems of GLUTAMINE or GLUTATHIONE metabolism.	5-Oxoproline,Pidolic Acid,Pyroglutamic Acid,5-Ketoproline,5-Oxopyrrolidine-2-Carboxylic Acid,Magnesium Pidolate,Pyroglutamate,Pidolate, Magnesium
D011919	Rats, Inbred Strains	Genetically identical individuals developed from brother and sister matings which have been carried out for twenty or more generations or by parent x offspring matings carried out with certain restrictions. This also includes animals with a long history of closed colony breeding.	August Rats,Inbred Rat Strains,Inbred Strain of Rat,Inbred Strain of Rats,Inbred Strains of Rats,Rat, Inbred Strain,August Rat,Inbred Rat Strain,Inbred Strain Rat,Inbred Strain Rats,Inbred Strains Rat,Inbred Strains Rats,Rat Inbred Strain,Rat Inbred Strains,Rat Strain, Inbred,Rat Strains, Inbred,Rat, August,Rat, Inbred Strains,Rats Inbred Strain,Rats Inbred Strains,Rats, August,Rats, Inbred Strain,Strain Rat, Inbred,Strain Rats, Inbred,Strain, Inbred Rat,Strains, Inbred Rat