A comparison of methods for measuring urinary ammonium

Cunarro, Julia; Weiner, Michael W.

doi:10.1038/ki.1974.41

Cited by 66 publications

(32 citation statements)

References 7 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The IRMA SL Series 2000 blood analysis system (Edison, NJ) measured venous plasma/blood pH and PCO 2 . Urine and plasma TCO 2 were measured with ultrafluorometry (20), urine titratable acidity by correction to ambient plasma pH by NaOH addition, and urine NH 4 + by the formalin titrametric (to ambient plasma pH) method (21). Urine N-acetyl b-D-glucosaminidase (UNAG) excretion, an index of kidney tubulointerstitial injury (22) and an index of kidney injury induced by dietary acid (11,23), was measured using a colorimetric assay (Boehringer Mannheim, Mannheim, Germany) (22) with a coefficient of variation of 9%.…”

Section: Methodsmentioning

confidence: 99%

A Comparison of Treating Metabolic Acidosis in CKD Stage 4 Hypertensive Kidney Disease with Fruits and Vegetables or Sodium Bicarbonate

Goraya

Simoni

et al. 2013

Clinical Journal of the American Society of Nephrology

351

277

View full text Add to dashboard Cite

SummaryBackground and objectives Current guidelines recommend Na + -based alkali for CKD with metabolic acidosis and plasma total CO 2 (PTCO 2 ) , 22 mM. Because diets in industrialized societies are typically acid-producing, we compared base-producing fruits and vegetables with oral NaHCO 3 (HCO 3 ) regarding the primary outcome of follow-up estimated GFR (eGFR) and secondary outcomes of improved metabolic acidosis and reduced urine indices of kidney injury.Design, setting, participants, & measurements Individuals with stage 4 (eGFR, 15-29 ml/min per 1.73 m 2 ) CKD due to hypertensive nephropathy, had a PTCO 2 level , 22 mM, and were receiving angiotensin-converting enzyme inhibition were randomly assigned to 1 year of daily oral NaHCO 3 at 1.0 mEq/kg per day (n=35) or fruits and vegetables dosed to reduce dietary acid by half (n=36).Results Plasma cystatin C-calculated eGFR did not differ at baseline and 1 year between groups. One-year PTCO 2 was higher than baseline in the HCO 3 group (21.261.3 versus 19.561.5 mM; P,0.01) and the fruits and vegetables group (19.961.7 versus 19.361.9 mM; P,0.01), consistent with improved metabolic acidosis, and was higher in the HCO 3 than the fruits and vegetable group (P,0.001). One-year urine indices of kidney injury were lower than baseline in both groups. Plasma [K + ] did not increase in either group.Conclusions One year of fruits and vegetables or NaHCO 3 in individuals with stage 4 CKD yielded eGFR that was not different, was associated with higher-than-baseline PTCO 2 , and was associated with lower-than-baseline urine indices of kidney injury. The data indicate that fruits and vegetables improve metabolic acidosis and reduce kidney injury in stage 4 CKD without producing hyperkalemia.

show abstract

Section: Methodsmentioning

confidence: 99%

A Comparison of Treating Metabolic Acidosis in CKD Stage 4 Hypertensive Kidney Disease with Fruits and Vegetables or Sodium Bicarbonate

Goraya

Simoni

et al. 2013

Clinical Journal of the American Society of Nephrology

351

277

View full text Add to dashboard Cite

show abstract

“…Urinary ammonium was measured by a Formalin titrimetric method. 19 Net acid excretion was calculated as the sum of titratable acidity and ammonium minus bicarbonate excretion. Fractional excretion of sodium and bicarbonate was calculated based on inulin clearance.…”

Section: Laboratory Proceduresmentioning

confidence: 99%

Renal acid-base excretion in normotensive salt-sensitive humans.

et al. 1993

View full text Add to dashboard Cite

Reduced extracellular pH and bicarbonate levels recently have been reported in normotensive saltsensitive subjects. To assess the possible role of altered renal acid-base handling in the perturbation of acid-base status in these individuals, we measured the renal acid-base excretion after an acute oral administration of either an alkali or acid load in normotensive salt-sensitive and salt-resistant men. Twenty-four young (22 to 29 years old), healthy male volunteers were placed on a low-salt diet (20 mmol NaCl per day) for 2 weeks with either 220 mmol NaCl or placebo added to the low-salt diet for 1 week each in a randomized single-blind crossover order. Salt sensitivity was defined as a significant drop in mean arterial pressure (>3 mm Hg, mean of 60 readings taken on the seventh day of each diet, P<.05) during the low-salt diet On the fifth and seventh days of each week, subjects were given an oral load of either sodium citrate (0.7 mmol/kg) or ammonium chloride (2.2 mmol/kg), respectively, in a randomized order, and arterial and urinary acid-base status was assessed at baseline and followed for 8 hours thereafter. According to the above definition, 13 subjects were considered salt sensitive. During the high-salt diet, mean arterial pressure was higher in the salt-sensitive than in the salt-resistant group (P<.01). Cumulative urinary bicarbonate excretion after the administration of sodium citrate was lower in the salt-sensitive than in the salt-resistant subjects during both the low-salt (46%, P<.001) and high-salt (32%, P<.0\) diets. Fractional sodium and bicarbonate excretion based on inulin clearance were likewise significantly lower in the salt-sensitive individuals after sodium citrate intake during both diets (P<.05), pointing to increased sodium and bicarbonate reabsorption. In contrast, net acid excretion after ammonium chloride was not different between the two groups. Our finding of an enhanced bicarbonate reabsorption in salt-sensitive men could indicate a compensatory renal adaptation to metabolic acid overproduction. This perturbation of renal bicarbonate excretion may contribute to sodium retention and thus salt sensitivity in genetically susceptible humans. (Hypertension. 1993^22:884-890.) KEY WORDS • hypertension, sodium-sensitive • acid-base equilibrium • sodium • ammonium chloride • ion exchange • metabolism • diet, sodium-restricted

show abstract

“…7 Samples were first diluted 1/20 in distilled water. A standard curve of ammonium chloride was also prepared by Age (yrs) 49.1 ± 13.0 (n = 19) 49.6 ± 11.6 (n = 67) NS Weight (kg) 79.3 ± 11.4 (n = 19) 80.4 ± 10.9 (n = 66) NS Ly systolic blood pressure (mm Hg) 124.2 ± 11.3 (n = 19) 159.3 ± 15.0 (n = 67) P Ͻ 0.001 Ly diastolic blood pressure (mm Hg)…”

Section: Measurement Of Urinary Ph Titratable Acidity and Ammoniummentioning

confidence: 99%

Urinary acid-base excretion in normotensives and hypertensives of African origin

Sagnella

Khong

et al. 2000

J Hum Hypertens

View full text Add to dashboard Cite

A comparison of methods for measuring urinary ammonium

Cited by 66 publications

References 7 publications

A Comparison of Treating Metabolic Acidosis in CKD Stage 4 Hypertensive Kidney Disease with Fruits and Vegetables or Sodium Bicarbonate

A Comparison of Treating Metabolic Acidosis in CKD Stage 4 Hypertensive Kidney Disease with Fruits and Vegetables or Sodium Bicarbonate

Renal acid-base excretion in normotensive salt-sensitive humans.

Urinary acid-base excretion in normotensives and hypertensives of African origin

Contact Info

Product

Resources

About