...Meena Haribal; Georg Jander ABSTRACT Plant roots incorporate inorganic nitrogen into the amino acids glutamine, glutamic acid, asparagine and aspartic acid, which together serve as the primary metabolites of nitrogen transport to other tissues. Given the preponderance of these four amino acids...

... glutamine concentration at HEA, from ∼3000 μmol kg –1 WM to 15,000 μmol kg –1 WM after 48 h, which is consistent with the hypothesis that glutamine production is associated with ammonia detoxification. Injection of the NMDA receptor antagonists MK801 (0.5–8 mg kg –1 ) or ethanol (1–8 mg kg –1 ) increased...

...L. A. Sanderson; P. A. Wright; J. W. Robinson; J. S. Ballantyne; N. J. Bernier SUMMARY Glutamine synthetase (GSase), the enzyme that catalyses the conversion of glutamate and ammonia to glutamine, is present at high levels in vertebrate brain tissue and is thought to protect the brain from elevated...

...Y. K. Ip; A. M. Loong; B. Ching; G. H. Y. Tham; W. P. Wong; S. F. Chew SUMMARY This study aimed to examine whether the stenohaline freshwater stingray, Potamotrygon motoro , which lacks a functional ornithine—urea cycle, would up-regulate glutamine synthetase (GS) activity and protein abundance...

... amino acid catabolism, and increased synthesis of certain non-essential amino acids. Here we report for the first time that glutamine is the major organic osmolyte in M. albus . Glutamine content increased to a phenomenal level of >12 μmol g –1 and >30 μmol g –1 in the muscle and liver...

...P. A. Wright; S. L. Steele; A. Huitema; N. J. Bernier SUMMARY The key strategy for coping with elevated brain ammonia levels in vertebrates is the synthesis of glutamine from ammonia and glutamate,catalyzed by glutamine synthetase (GSase). We hypothesized that all four GSase isoforms ( Onmy-GS01...

... and/or glutamine in their brains, and if acute ammonia intoxication could be prevented by the administration of methionine sulfoximine [MSO; an inhibitor of glutamine synthetase (GS)] or MK801 [an antagonist of n -methyl d -aspartate type glutamate (NMDA) receptors]. For P. schlosseri and B. boddaerti exposed...

... of alanine in P. expansa is mainly connected with intracellular osmoregulation. Although 8.5–16.1% of the TFAA pool of P. expansa was attributable to glutamine, the glutamine contents in the adductor muscle, foot muscle,hepatopancreas and mantle were unaffected by 17 days of exposure to seawater. However...

... previously for other fish species. Consequently, contrary to previous reports, there were significant decreases in the ammonia content of the brain of P. schlosseri throughout the 24 h period post-feeding, accompanied by a significant decrease in brain glutamine content between 12 h and 24 h. References...

... with the problem of excess ammonia are described. The fish can (1) reduce ammonia production through reduction in protein and/or amino acid catabolism; (2)reduce ammonia production and obtain energy through partial amino acid catabolism leading to alanine formation; (3) detoxify ammonia to glutamine;(4) tolerate...

... exposure. Instead, ammonia produced through amino acid catabolism was detoxified to glutamine, leading to the accumulation of glutamine in the body during the first 72 h of aerial exposure. Complimenting the increased glutamine formation was a significant increase in glutamine synthetase activity...

... of air-exposed fish, but levels of both urea and some FAAs (primarily alanine and glutamine) were up to twofold higher after 10 days. The activities of the ornithine–urea cycle enzymes carbamoyl phosphate synthetase III and ornithine transcarbamylase increased (by approximately 30 % and 36...

... in normal acid–base regulation. 01 12 1993 © 1994 by Company of Biologists 1994 Lake Magadi urea acid–base balance high pH liver ornithine–urea cycle ammonia glutamine Oreochromis alcalicus grahami The tilapia Oreochromis alcalicus grahami lives in the highly alkaline...

... exposure. However, haemolymph total ammonia concentrations generally remained below 5 mmol l − 1 ( =0.37 Pa) over the range of ambient ammonia levels used (6.6–165 Pa). Following a 7-day loading period, whole-animal glutamine (Gln) and glutamate (Glu) levels increased in direct proportion to ambient...

...K. Tiihonen; M. Nikinmaa 17 7 1991 © 1991 by Company of Biologists 1991 carp erythrocyte metabolism lactate pyruvate glutamine glucose glutamate aspartate isoleucine adenosine Cyprinus carpio Compared with the anucleated mammalian erythrocytes, which rely...

... transport. L-Glutamine also seems to be metabolized just like L-alanine because: L-glutamine acted from inside the enterocyte; DNP inhibited the effects of L-glutamine; neither of the effects of L-glutamine and L-alanine were additive but they were mutually complementary; L-glutamine also enhanced ouabain...