The mechanisms by means of which phenylephrine stimulates glutamine metabolism were studied in isolated rat hepatocytes. In the first 2 min after phenylephrine addition there was a rapid fall in the concentrations of intracellular 2-oxoglutarate and glutamate, presumably owing to activation of 2-oxoglutarate dehydrogenase. This was followed 2-3 min later by activation of glutaminase and by incr...

Context Specific plasma amino acid (AA) profiles including elevated postabsorptive branched-chain amino acids (BCAAs) have been associated with insulin resistance (IR), mostly estimated by homeostatic model assessment. This study assessed the associations of postabsorptive AAs with IR directly measured by insulin-mediated glucose disposal and determined the quantitative value of AAs and convent...

Dialysis disequilibrium syndrome (DDS) is characterized by the neurologic deterioration and cerebral edema that occurs after hemodialysis. To investigate the pathogenesis of DDS, the effects of rapid hemodialysis on brain electrolytes, urea, and several organic osmolytes were studied in the rat. Forty-two h after bilateral ureteral ligation, 11 uremic rats were hemodialyzed for 90 min, yielding...

Embryos and larvae of the African catfish Clarias gariepinus excrete significant quantities of urea. The present study focused on the potential urea-generating pathways during early development of this teleost; uricolysis, argininolysis and the ornithine-urea cycle (OUC). Uricase, allantoinase, allantoicase and ureidoglycollate lyase of the uricolytic pathway were expressed in all early life st...

The conversion of ammonia into urea by the human liver requires the coordinated function of the 6 enzymes and 2 transporters of the urea cycle. The initial and rate-limiting enzyme of the urea cycle, carbamylphosphate synthetase 1 (CPS1), requires an allosteric activator, N-acetylglutamate (NAG). The formation of this unique cofactor from glutamate and acetyl Coenzyme-A is catalyzed by N-acetyl...

Homocitrulline arises from the reaction between cyanate and the epsilon-amino group of lysine residues; in milk, cyanate derives from heat-induced urea breakdown. Since homocitrulline levels were unknown in heated milk, its formation was studied in the temperature range 100-150 degrees C. Firstly, an analysis method based on ion-exchange chromatography using an amino acid analyser was developed...

Milk production potential of buffaloes can be exploited through fulfilling nutritional requirements in terms of protein and energy. Two essential amino acids lysine (Lys) and methionine (Met) are limiting amino acids for optimum milk production in early lactation of these animals and are derived from dietary source. The objective of the present study was to analyze the effect of rumen protected...

Tannins are a diverse group of plant phenolic compounds. Condensed tannins (CTs) represent major subgroup and were extracted from tilia (Tilia L.) flowers black locust (Robinia pseudoacacia) leaves. These extracts examined for their effects on the metabolic profile chicken caeca. By using in vitro, nuclear magnetic resonance (1H-NMR), which was combined with multivariate statistics, current stu...