Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UNIPROT:P01275 (glucagon)
 26,492 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Foetal-rat hepatocytes were cultured in primary monolayer culture, and activity changes of argininosuccinate synthetase (ASS, EC 6.3.4.5) and argininosuccinase (ASL, EC 4.3.2.1) were followed under defined hormone conditions. In hormone-free medium, cultured cells maintained the enzyme activities at values equal to those of freshly isolated cells for at least 3 days. Continuous addition of dexamethasone produced the development of the two enzyme activities, but only after the first 20h of culture. Under these conditions, urea production by the foetal hepatocytes was concomitantly increased in the culture medium. Pretreatment with dexamethasone for 20h was sufficient to produce the development of ASL activity within the 2 following days. Introduced alone, glucagon induced an increase of ASL activity, but did not affect the ASS activity. The most powerful stimulation of ASS and ASL could be observed in cultured hepatocytes if glucagon and dexamethasone were added simultaneously or sequentially. These results indicated that the development of the receptor complex for the induction of urea-cycle enzymes appears early before birth and established that glucocorticoids amplify the glucagon stimulation of these enzyme activities during foetal life.
 ...
PMID:Hormonal regulation of two urea-cycle enzymes in cultured foetal hepatocytes. 666 Nov 96

The in vivo effects of three new analogs of somatostatin (ASS-51, ASS-52 and ASS-53 analogs) on GH, insulin and glucagon were studied in WKY rats. The solid phase method was used for the synthesis of ASS. Octreotide and ASS were given iv. in a dose of 0.05 &mgr;g/kg per animal in a time-dependent manner. ASS-52 and ASS-53 were longer acting and more potent somatostatin analogs when compared to octreotide in producing the inhibition of GH. ASS-51 was found to be the most potent and selective inhibitor of insulin and glucagon release. Our results show that the increased inhibitory effect and the higher selectivity of the new somatostatin analogs may result from the differences in their chemical structure. ASS-52 is most active in inhibiting GH release. The mechanism by which ASS-52 inhibits preferentially GH release may involve the opioid system and the activation of GABA-ergic receptors. In studies in vitro ASS-52 inhibited GH release from pituitary cells" culture.
 ...
PMID:New analogs of somatostatin: inhibiting effectively GH, glucagon and insulin levels. 1146 19

Argininosuccinate synthetase (ASS, EC 6.3.4.5) catalyses the condensation of citrulline and aspartate to form argininosuccinate, the immediate precursor of arginine. First identified in the liver as the limiting enzyme of the urea cycle, ASS is now recognized as a ubiquitous enzyme in mammalian tissues. Indeed, discovery of the citrulline-NO cycle has increased interest in this enzyme that was found to represent a potential limiting step in NO synthesis. Depending on arginine utilization, location and regulation of ASS are quite different. In the liver, where arginine is hydrolyzed to form urea and ornithine, the ASS gene is highly expressed, and hormones and nutrients constitute the major regulating factors: (a) glucocorticoids, glucagon and insulin, particularly, control the expression of this gene both during development and adult life; (b) dietary protein intake stimulates ASS gene expression, with a particular efficiency of specific amino acids like glutamine. In contrast, in NO-producing cells, where arginine is the direct substrate in the NO synthesis, ASS gene is expressed at a low level and in this way, proinflammatory signals constitute the main factors of regulation of the gene expression. In most cases, regulation of ASS gene expression is exerted at a transcriptional level, but molecular mechanisms are still poorly understood.
 ...
PMID:Argininosuccinate synthetase from the urea cycle to the citrulline-NO cycle. 1270 47