Apparent Free Amino Acids in Deproteinized Plasma of Normal and Uremic Persons1

Salisbury, Peter F.; Dunn, Max S.; Murphy, Edward A.

doi:10.1172/jci103519

Cited by 28 publications

(8 citation statements)

References 16 publications

(11 reference statements)

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“…Regarding amino acid concentrations in uremia, in accordance wvith previous observations (22,(35)(36)(37), uremic subjects demonstrated increases in plasma, glycine, cystine, citrulline, proline, and taurine, and decreases in tyrosine, valine, and a-aminobutyrate. The amino acid pattern in uremia differed from prolonged starvation in which circumstance hypoalaninemia is a striking find (38), thus it suggests that the alterations observed in uremia are not primarily the result of caloric deprivation.…”

Section: Discussionsupporting

confidence: 87%

“…These data suggest that nondietary factors contribute to the changes observed in amino acids in uremia. The increased citrulline concentration may reflect alterations in urea cycle activity; elevated arginine levels have also been observed in uremic patients (22,(35)(36)(37). Particularly noteworthy are the normal levels of serine in the uremic group (Table I).…”

Section: Discussionmentioning

confidence: 94%

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Influence of uremia and hemodialysis on the turnover and metabolic effects of glucagon.

Sherwin¹,

Bastl²,

Finkelstein³

et al. 1976

J. Clin. Invest.

195

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A B S T R A C T To evaluate the mechanism and role of hyperglucagonemia in the carbohydrate intolerance of uremia, 19 patients with chronic renal failure (12 of whom had undergone chronic hemodialysis for at least 11 mo) and 35 healthy control subjects were studied. Plasma glucagon, glucose, and insulin were measured in the basal state, after glucose ingestion (100 g), after intravenous alanine (0.15 g/kg), and during a 3-h continuous infusion of glucagon (3 ng/kg per min) which in normal subjects, raised plasma glucagon levels into the upper physiological range.Basal concentrations of plasma glucagon, the increment in glucagon after infusion of alanine, and postglucose glucagon levels were three-to fourfold greater in uremic patients than in controls. The plasma glucagon increments after the infusion of exogenous glucagon were also two-to threefold greater in the uremics. The metabolic clearance rate (MCR) of glucagon in uremics was reduced by 58% as compared to controls. In contrast, the basal systemic delivery rate (BSDR) of glucagon in uremics was not significantly different from controls.Comparison of dialyzed and undialyzed uremics showed no differences with respect to plasma concentrations, MCR, or BSDR of glucagon. However, during the infusion of glucagon, the increments in plasma glucose in undialyzed uremics were three-to fourfold greater than in dialyzed uremics or controls. When the glucagon infusion rate was increased in controls to 6 ng/kg per min to produce increments in plasma glucagon comparable to uremics, the glycemic response remained approximately twofold greater in the undialyzed uremics. The plasma glucose response to glu- cagon in the uremics showed a direct linear correlation with oral glucose tolerance which was also improved with dialysis. The glucagon infusion resulted in a 24% reduction in plasma alanine in uremics but had no effect on alanine levels in controls. It is concluded that (a) hyperglucagonemia in uremia is primarily a result of decreased catabolism rather than hypersecretion of this hormone; (b) sensitivity to the hyperglycemic effect of physiological increments in glucagon is increased in undialyzed uremic patients; and (c) dialysis normalizes the glycemic response to glucagon, possibly accounting thereby for improved glucose tolerance despite persistent hyperglucagonemia. These findings thus provide evidence of decreased hormonal catabolism contributing to a hyperglucagonemic state, and of altered tissue sensitivity contributing to the pathophysiological action of this hormone.

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Section: Discussionsupporting

confidence: 87%

Section: Discussionmentioning

confidence: 94%

Influence of uremia and hemodialysis on the turnover and metabolic effects of glucagon.

Sherwin¹,

Bastl²,

Finkelstein³

et al. 1976

J. Clin. Invest.

195

View full text Add to dashboard Cite

show abstract

“…The finding of increased a-amino nitrogen after hydrolysis of deproteinized plasma from patients with uremia confirms the findings of previous investigators (2)(3)(4)(5)(6)(7). The dialysis experiments indicated that the substances giving rise to increased ninhydrin color after alkaline hydrolysis were of low molecular weight.…”

Section: Discussionsupporting

confidence: 91%

“…Since free amino acids also contribute to the nonprotein, nonurea nitrogen of plasma, several investigators have determined the amino acid composition of plasma from both normal subjects and patients with uremia. They have shown that in uremia, concentrations of the individual plasma are normal or that such alterations in concentrations as exist are slight and probably insignificant (3)(4)(5)(6)(7). In addition, the total a-amino nitrogen in plasma of patients with uremia remains approximately normal (3)(4)(5)(6)(7)(8)(9)(10).…”

mentioning

confidence: 99%

“…They have shown that in uremia, concentrations of the individual plasma are normal or that such alterations in concentrations as exist are slight and probably insignificant (3)(4)(5)(6)(7). In addition, the total a-amino nitrogen in plasma of patients with uremia remains approximately normal (3)(4)(5)(6)(7)(8)(9)(10). However, studies in which deproteinized plasma was hydrolyzed revealed that some anmino acids are variably increased in concentration (34).…”

mentioning

confidence: 99%

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