Biomaterial Database

Insulin antagonism of dexamethasone-induced increase or argininosuccinate synthetase and argininosuccinate lyase activities in cultured fetal rat liver. 1977

N C Räihä, and E Edkins

In fetal rat liver explants maintained in organ culture, the addition of dexamethasone (4.6 X 10(-6)M) produced a 2- to 3-fold increase in the activity of argininosuccinate synthetase and in argininosuccinate lyase after 24 and 48 h of incubation. Insulin (1.8 X 10(-6)M) alone had no effect on the enzyme activities, but when incubated together with dexamethasone, it abolished the dexamethasone-induced increase of argininosuccinate synthetase and inhibited the argininosuccinate lyase activity by 80%, at 24 h. At 48 h, the inhibition of both enzyme activities was 68%. The antagonistic effect of insulin on the dexamethasone action is discussed in relation to the mechanism of perinatal enzyme induction. Hyperinsulinemia may interfere with the development of enzyme systems during the perinatal period. This could have relevance in the care of infants of diabetic mothers.

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
D008025	Ligases	A class of enzymes that catalyze the formation of a bond between two substrate molecules, coupled with the hydrolysis of a pyrophosphate bond in ATP or a similar energy donor. (Dorland, 28th ed) EC 6.	Ligase,Synthetases,Synthetase
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
D008190	Lyases	A class of enzymes that catalyze the cleavage of C-C, C-O, and C-N, and other bonds by other means than by hydrolysis or oxidation. (Enzyme Nomenclature, 1992) EC 4.	Desmolase,Desmolases,Lyase
D009924	Organ Culture Techniques	A technique for maintenance or growth of animal organs in vitro. It refers to three-dimensional cultures of undisaggregated tissue retaining some or all of the histological features of the tissue in vivo. (Freshney, Culture of Animal Cells, 3d ed, p1)	Organ Culture,Culture Technique, Organ,Culture Techniques, Organ,Organ Culture Technique,Organ Cultures
D011247	Pregnancy	The status during which female mammals carry their developing young (EMBRYOS or FETUSES) in utero before birth, beginning from FERTILIZATION to BIRTH.	Gestation,Pregnancies
D003907	Dexamethasone	An anti-inflammatory 9-fluoro-glucocorticoid.	Hexadecadrol,Decaject,Decaject-L.A.,Decameth,Decaspray,Dexasone,Dexpak,Hexadrol,Maxidex,Methylfluorprednisolone,Millicorten,Oradexon,Decaject L.A.
D004790	Enzyme Induction	An increase in the rate of synthesis of an enzyme due to the presence of an inducer which acts to derepress the gene responsible for enzyme synthesis.	Induction, Enzyme
D005260	Female		Females
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