Spectrophotometric Quantitation of Plasma and Urinary Amino Nitrogen with Fluorodinitrobenzene

Goodwin, Jesse F.; Schoenfeld, R.; Ryland, Margaret E.

doi:10.1016/b978-0-12-609106-9.50014-2

Cited by 99 publications

(30 citation statements)

References 22 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Indeed, FHNC has been shown to depend on quantitative liver function (5,7,23,271, and in these experiments we were able to confirm a correlation between FHNC and other quantitative liver function parameters. Most important, a direct correlation was shown between liver function -measured by galactose elimination capacity and antipyrine clearance-and the ability of glucagon to ameliorate the dynamics of a-amino nitrogen-to-urea nitrogen conversion.…”

Section: Discussionsupporting

confidence: 75%

Unresponsiveness of hepatic nitrogen metabolism to glucagon infusion in patients with cirrhosis: Dependence on liver cell failure

et al. 1993

View full text Add to dashboard Cite

Glucagon exerts an up-regulatory effect on hepatic nitrogen metabolism in healthy subjects, but its potential role in the presence of liver failure is uncertain. The effects of glucagon on urea synthesis and hepatic nitrogen clearance during alanine infusion were studied in five control subjects and six cirrhotic patients in paired experiments at spontaneous glucagon concentrations and at high physiological glucagon levels (approximately 300 to 500 pmol.L-1) induced by a 7.5-hr continuous glucagon infusion. In all experiments the urea nitrogen synthesis rate increased linearly with increasing alpha-amino-nitrogen concentrations. At spontaneous glucagon concentrations the dynamics of alpha-amino nitrogen to urea nitrogen conversion (functional hepatic nitrogen clearance) were significantly reduced in cirrhosis (23.2 +/- 6.7 L.hr-1 vs. 35.3 +/- 8.0 L.hr-1, p < 0.05) in relation to decreased liver function. Glucagon superinfusion caused a 63% increase in the dynamics of the process in controls (57.7 +/- 11.0 L.hr-1; p vs. spontaneous glucagon, p < 0.01), whereas in cirrhosis it increased on average by only 15% (26.7 +/- 10.7; p = NS). The glucagon-induced change in functional hepatic nitrogen clearance significantly correlated with galactose elimination capacity and antipyrine clearance (r = 0.905 and 0.964, respectively). Glucagon, in high physiological concentrations achieved with glucagon infusion, does not produce significant effects on hepatic nitrogen metabolism in cirrhosis. The reduced sensitivity of the cirrhotic liver to glucagon seems to be dependent on decreased hepatocellular function. These data do not support the role of glucagon as a "catabolic" hormone in cirrhosis.

show abstract

Section: Discussionsupporting

confidence: 75%

Unresponsiveness of hepatic nitrogen metabolism to glucagon infusion in patients with cirrhosis: Dependence on liver cell failure

et al. 1993

View full text Add to dashboard Cite

show abstract

“…Blood urea concentration was measured by the urease-Berthelot method [21] and total blood a-amino-N concentration by the dinitroflourobenzene method [22]. Serum IGF-I concentration was measured by an in-house RIA using a polyclonal rabbit antibody (Nichols Institute Diagnostics, San Capistiano, Ca) and recombinant human IGF-I as standard (Amersham International, Amersham, Bucks, UK).…”

Section: Analysesmentioning

confidence: 99%

Growth hormone and growth hormone secretagogue effects on nitrogen balance and urea synthesis in steroid treated rats

Aagaard

Grøfte

Greisen

et al. 2009

Growth Hormone & IGF Research

View full text Add to dashboard Cite

“…Blood urea concentration was measured by the urease-Berthelot method [10] and blood total alpha-amino-N concentration by the dinitrofluorobenzene method [11]. Glucose concentration in blood and in urine was measured by the glucose oxidase technique, by a glucose analyser (Yellow Springs Instruments, Yellow Springs, Ohio, USA).…”

Section: Analysesmentioning

confidence: 99%

Exogenous hyperglucagonaemia in insulin controlled diabetic rats increases urea excretion and nitrogen loss from organs

Almdal

Vilstrup

1988

Diabetologia

View full text Add to dashboard Cite

Summary. In order to study the effect of hyperglucagonaemia on nitrogen metabolism in diabetes, zinc protamin glucagon 60 ~Lg was injected subcutaneously 3 times daily for 4 weeks into streptozotocindiabetic rats (n=5), adequately treated with long acting insulin. This raised the plasma concentration of glucagon to 725 ___ 125 (mean___ SEM), which is not different from that found in portal blood of uncontrolled diabetic rats: 400 + 75 ng/1. The controls were 5 diabetic rats treated with insulin alone and 5 non-diabetic rats.Compared with control rats the nitrogen balance was reduced (p < 0.05) and the nitrogen contents of carcass, heart, intestines, and kidneys were reduced by 15-30% (p< 0.05) in the glucagon treated rats. The hepatic capacity of urea synthesis and the alanine elimination rate were determined in the 3 above-mentioned groups, and confirmed in 3 identical groups followed for only 2 weeks; and in addition in a group of glucagon treated diabetic rats, where the long acting glucagon was substituted by neutral insulin the last two days before investigation. The capacity of urea-N synthesis and the alanine elimination rate were, respectively, in control rats: 9.6 + 0.8 and 5.9 +_ 0.3 p.mol/(min 100 g body weight), in insulin treated diabetic rats: 8.5_+ 0.7 and 5.4_+ 0.6 ~Lmol/(min 100g body weight), in glucagon treated rats: 6.3 + 0.4 (lower than controls, p< 0.05) and 10.4 + 0.4 (higher than controls, p< 0.05) ~mol/(min 100 g body weight), and in glucagon treated rats given neutral insulin: 20.7 +_ 1.6 and 10.9_+ 0.3 p~mol/(min 100 g body weight) (both higher than controls, p< 0.05). Hyperglucagonaemia in itself leads to loss of nitrogen from organs, probably by an increased hepatic conversion of amino-nitrogen to urea-nitrogen, as evidenced by the increased urea excretion. This proceeds despite an insulin induced decrease in the capacity of urea synthesis and may thus rather be attributed to changes in the affinity of urea synthesis for amino-nitrogen.

show abstract

Spectrophotometric Quantitation of Plasma and Urinary Amino Nitrogen with Fluorodinitrobenzene

Cited by 99 publications

References 22 publications

Unresponsiveness of hepatic nitrogen metabolism to glucagon infusion in patients with cirrhosis: Dependence on liver cell failure

Unresponsiveness of hepatic nitrogen metabolism to glucagon infusion in patients with cirrhosis: Dependence on liver cell failure

Growth hormone and growth hormone secretagogue effects on nitrogen balance and urea synthesis in steroid treated rats

Exogenous hyperglucagonaemia in insulin controlled diabetic rats increases urea excretion and nitrogen loss from organs

Contact Info

Product

Resources

About