Accelerated selective short column chromatography of neutral and acidic amino acids on a beckman-spinco analyzer, modified for simultaneous analysis of two samples

Scriver, Charles R.; Davies, Eluned; Lamm, Peter

doi:10.1016/s0009-9120(67)80022-5

Cited by 27 publications

(13 citation statements)

References 6 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The supernatant was recovered by centrifugation at 10,000 X g, for 10 min at 4°. The deproteinized plasma was applied to the resin columns of a Beckman/Spinco amino acid analyzer [33], modified for simultaneous analysis of small volume samples on "acidic" and "basic" columns [30]. The error of analysis by this method is not more than ±3% for each amino acid.…”

Section: Methodsmentioning

confidence: 99%

The Effect of Intravenous Glucagon on Plasma Amino Acids in the Newborn

et al. 1973

View full text Add to dashboard Cite

ExtractThe relationship between glucagon stimulation at a pharmacologic dose level (300 jug/kg) and amino acids in systemic venous plasma was examined in four groups of newborn infants. Full term infants (FT), (mean age, 12.5 hr), infants of diabetic mothers (IDM), (mean age, 3.33 hr), infants who were small for gestational age (SGA), (mean age, 7.5 hr), were studied on the day of birth either before, or 4 hr after the first feeding; FT infants were studied on the 3rd day of life (mean age, 80 hr), 4 hr after feeding.The mean total amino acid concentration in venous plasma on the day of birth is 2,999 ± 147 /imol/liter in FT infants, 2,952 ± 536 /xmol/liter in IDM infants, and 1,867 ± 320 Mmol/liter in the SGA group (P < 0.005 compared with FT group). Since plasma amino acid levels normally fall rapidly, the level in the IDM group is lower than expected for the postnatal age of this group on the day of birth. Several amino acids, notably, glutamine plus asparagine, and glycine contribute to the very low total amino acid level in SGA infants. Total amino acid concentration in FT infants falls to 2,444 =1= 395 /imol/liter by the 3rd day of life. Two important glucogenic amino acids, glycine and alanine, account for half of the net decline, whereas the branched chain amino acids show a net rise in plasma by the 3rd day.Glucagon infusion produces a hypoaminoacidemic response at 30 min on the 3rd day of life, a reaction which resembles that of the adult. Glutamine plus asparagine (absolute change (A), -165 jumol/liter), glycine (A, -55 /anol/liter), alanine (A, -45 Mmol/liter), and proline (A, -40 /xmol/liter), the amino acids with the most important gluconeogenic functions in liver and kidney, account for about 60% of the total net decline in the total plasma amino acid level.The response to glucagon is attenuated on the day of birth in the FT infant. The IDM group is insensitive to glucagon, whereas the response in the SGA group mimics FT infants.Blood glucose on the day of birth is depressed in IDM (20.2 ± 4.4 mg/100 ml) and SGA (28.6 ± 3.5 mg/100 ml) infants compared with full term infants (45 ± 4.7 mg/100 ml). Basal serum insulin on the day of birth is elevated fivefold above FT values (2.0 ± 0.77 /tU/ml) in IDM and SGA groups. All groups have an insulinemic response to glucagon (A, > + 23 /iU/ml) and the peak insulin response is highest in the SGA group. The basal level of serum growth hormone is elevated in the SGA group on the day of birth (51.9 ± 15.6 ng/ml) compared with full term infants (15.1 ± 4

show abstract

Section: Methodsmentioning

confidence: 99%

The Effect of Intravenous Glucagon on Plasma Amino Acids in the Newborn

et al. 1973

View full text Add to dashboard Cite

show abstract

“…Quantitative: The amino acid content of urine and plasma was measured by elution chromatography on ion exchange resins according to the methods of SPACK-MAN, STEIN and MOORE [32] on a Beckman-Spinco model 120 amino acid analyzer modified for simultaneous analysis of 'neutral' and 'basic' amino acids [30]. The error of analysis by this method averages less than 3 percent.…”

Section: Methodsmentioning

confidence: 99%

Hyperdibasicaminoaciduria: An Inherited Disorder of Amino Acid Transport[34]

Whelan

Scriver

1968

Pediatr Res

View full text Add to dashboard Cite

“…The concentrations of GABA and glutamate were measured by elution chromatography on ion exchange resin columns using a Beckman-Spinco amino acid analyzer modified for simultaneous post-term kidney is still two to threefold greater than in fetal analysis of acidic and basic amino acids (18). T h e tissue was tissue.…”

Section: Gaba Determinationmentioning

confidence: 99%

Ontogeny of L-Glutamic Acid Decarboxylase and γ-Aminobutyric Acid Concentration in Human Kidney

1975

View full text Add to dashboard Cite

Pediat. Res. 9: 484-487 (1975) Extract particular importance in man, who extracts glutamine from the Mature human renal cortex contains y-aminobutyric acid (GABA) at concentrations on the order of 0.2 p n o l / g wet wt and about half of that concentration in fetal kidney.a -A m i n o b u t y r i c acid h u m a n kidney g l u t a m i c acid decarboxylase pyridoxal p h o s p h a tThe pyridoxal-5'-phosphate (PLP)-dependent enzyme, Lglutamic acid decarboxylase (GAD), catalyzes the conversion of L-glutamate to GABA. The PLP-saturated GAD activity in post-term ( 1 day-9 years) renal cortex homogenate is 0.94 A 0.38 p n o l CO, formed/g wet wt/hr (Table 1). The corresponding GAD activity in fetal renal cortex, in the midtrimester and early third trimester, is 0.28 0.19 p n o l CO, formed/g wet wt/hr (P < 0.01 vs. post-term activity). GAD activity increases during gestation to reach levels at birth equivalent to mature kidney. When corrections are made for the difference in tissue water between fetal and mature kidney, they do not ablate the post-term increase in GAD activity.Renal GAD was undersaturated with P L P in 12 of 21 specimens examined; 8 of these specimens were of fetal origin (Table 1 and Fig. 2). Undersaturation was revealed when addition of P L P (0.24 m M ) to the homogenate stimulated activity by 2 5 3 0 0 % in the 12 specimens. GAD activity in rat kidney binds P L P avidly and is always saturated with P L P under the normal laboratory conditions of vitamin B, nutrition. Undersaturation of renal GAD in man may imply inadequate endogenous availability of vitamin B, coenzyme.The GABA pathway in mammalian kidney has been implicated in the maintenance of normal acid-base balance. Renal G A D is increased in the postnatal subject relative to fetal GAD activity in support of this hypothesis. Undersaturation of fetal GAD with its PLP-coenzyme in two-thirds of the fetal specimens may have implications concerning intrauterine nutrition and renal development.

show abstract

Accelerated selective short column chromatography of neutral and acidic amino acids on a beckman-spinco analyzer, modified for simultaneous analysis of two samples

Cited by 27 publications

References 6 publications

The Effect of Intravenous Glucagon on Plasma Amino Acids in the Newborn

The Effect of Intravenous Glucagon on Plasma Amino Acids in the Newborn

Hyperdibasicaminoaciduria: An Inherited Disorder of Amino Acid Transport[34]

Ontogeny of L-Glutamic Acid Decarboxylase and γ-Aminobutyric Acid Concentration in Human Kidney

Contact Info

Product

Resources

About