The renal excretion of hydrogen ion in renal tubular acidosis

Asidosis tubular renal (ATR) merupakan tubulopati ginjal yang jarang terjadi, dimana terdapat ketidakmampuan ginjal untuk menjaga perbedaan pH normal antara darah dan lumen tubulus ginjal. Pada kondisi ini terjadi gangguan pengasaman urin disebabkan gangguan reabsorbsi bikarbonat, gangguan ekskresi ion hidrogen, atau keduanya sehingga mengakibatkan asidosis metabolik. ATR ditandai dengan adanya asidosis metabolik dengan senjang anion plasma yang normal, hiperkloremik dan laju filtrasi glomerulus normal. ATR terbagi menjadi 3 tipe utama, yaitu ATR tipe 1 (ATR distal), tipe-2 (ATR proksimal), dan tipe 4 (ATR hiperkalemia). ATR distal merupakan ATR yang disebabkan oleh defek pada tubulus distal ginjal, dimana defek ini menyebabkan gangguan pada sekresi ion hidrogen. Beberapa penelitian menunjukkan bahwa ATR tipe 1 dikaitkan dengan mutasi genetik. Mutasi genetik herediter dapat autosomal dominan atau autosomal resesif. Gambaran klinis dapat mencakup kelainan pertumbuhan tulang, kelemahan atau kelumpuhan otot, deposit kalsium di ginjal, anoreksia, muntah, konstipasi, diare, dehidrasi, dan poliuria. Telah dilaporkan kasus pasien wanita usia 19 tahun dengan keluhan utama kelemahan di kedua tangan dan kaki. Dari penelusuran klinis dan laboratorium didapatkan hipokalemia dan berdasarkan pendekatan hipokalemia dengan HCO3- rendah dan pH urine >5,5, diagnosis pada pasien ini ditegakkan sebagai asidosis tubulus renal distal (ATRd).Kata kunci: ATR, ATRd, asidosis metabolik, hiperkloremik, hipokalemia AbstractRenal tubular acidosis (RTA) is a condition caused by the inability of the kidneys to maintain normal pH differences between the blood and tubules lumen of the kidney. Renal tubular acidosis is a rare kidney tubulopathy. In this condition, urine acidification is caused by bicarbonate reabsorption, disruption of hydrogen ion excretion, or both, resulting in metabolic acidosis. RTA is characterized by metabolic acidosis with normal plasma anion, hyperchloremic gaps and normal glomerular filtration rates. RTA is divided into 3 main types, namely type 1 RTA (distal RTA), type-2 (proximal RTA), and type 4 (hyperkalemia RTA). Distal RTA caused by defects in the distal tubules of the kidney, where these defects cause interference with the hydrogen ion secretion. Several studies have shown that type 1 RTA is associated with genetic mutations. Hereditary genetic mutations can be autosomal dominant or autosomal recessive. Clinical features can include bone growth disorders, muscle weakness or paralysis, calcium deposits in the kidneys, anorexia, vomiting, constipation, diarrhea, dehydration, and polyuria. There has been a reported case of a 19-year-old female patient with a chief complaint weakness in both hands and feet. From clinical and laboratory investigations, it was found that hypopotassium and based on the hypokalemia approach with low HCO3- and urine pH >5,5, the diagnosis in this patient was established as a distal renal tubular acidosis (RTAd) Keywords: RTA, RTAd ,metabolic acidosis, hypopotassium, hiperchloremic

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Renal Excretion of Ammonium in Renal Tubular Acidosis

The Tohoku Journal of Experimental Medicine ◽

10.1620/tjem.114.301 ◽

1974 ◽

Vol 114 (4) ◽

pp. 301-313

Author(s):

RYUJI SHIOJI ◽

YASUHIKO SASAKI ◽

YOTARO HURUKAWA ◽

HIROSHI SAITO ◽

YUICHI MICHIMATA ◽

...

Keyword(s):

Renal Tubular Acidosis ◽

Renal Excretion ◽

Renal Tubular

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Absence of vacuolar H(+)-ATPase pump in the collecting duct of a patient with hypokalemic distal renal tubular acidosis and Sjögren's syndrome.

Journal of the American Society of Nephrology ◽

10.1681/asn.v62295 ◽

1995 ◽

Vol 6 (2) ◽

pp. 295-301

Author(s):

P E DeFranco ◽

L Haragsim ◽

P G Schmitz ◽

B Bastani

Keyword(s):

Renal Biopsy ◽

Renal Tubular Acidosis ◽

Collecting Duct ◽

Band 3 ◽

Distal Renal Tubular Acidosis ◽

Hydrogen Ion ◽

Intercalated Cells ◽

Band 3 Protein ◽

Ion Secretion ◽

Renal Tubular

Distal renal tubular acidosis (dRTA) is a common complication of autoimmune connective tissue diseases. The underlying pathophysiology of renal tubular acidosis in these syndromes is frequently characterized by impaired hydrogen ion secretion, i.e., secretory defect dRTA. However, the precise molecular events leading to this disturbance remain poorly understood. An opportunity was recently afforded to examine the ultrastructural features of the collecting duct in a patient with Sjögren's syndrome and secretory defect dRTA. Immunocytochemical analysis of a renal biopsy obtained 12 months after the patient's initial presentation demonstrated a complete absence of vacuolar H(+)-ATPase in the collecting duct. Antibodies to the 31- and 56-kd kidney-specific subunits of the H(+)-ATPase pump were used to characterize pump distribution. Interestingly, although antiserum to the CI-:HCO3- anion exchanger (band-3 protein) reacted strongly with normal human kidney and the patient's red blood cells, no immunoreactivity was observed in the patient's collecting duct epithelium. Importantly, electron microscopy of the patient's renal biopsy specimen disclosed cells that ultrastructurally were indistinguishable from intercalated cells. These results suggest that the functional basis of impaired hydrogen ion secretion in this patient was secondary to the absence of intact H(+)-ATPase pumps rather than defective pump function or distribution. The presence of intercalated cells ultrastructurally, but the absence of discernible staining for band-3 protein and H(+)-ATPase, also suggests that the defect in proton secretion may represent a defect involving the assembly of at least two of the ion transport pumps essential for the normal maintenance of acid-base homeostasis by the intercalated cells.(ABSTRACT TRUNCATED AT 250 WORDS)

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Calcium and Hydrogen Ion Metabolism in Children with Classic (Type I/Distal) Renal Tubular Acidosis

Annals of Nutrition and Metabolism ◽

10.1159/000176480 ◽

1981 ◽

Vol 25 (2) ◽

pp. 65-78 ◽

Cited By ~ 10

Author(s):

James.C.M. Chan

Keyword(s):

Renal Tubular Acidosis ◽

Distal Renal Tubular Acidosis ◽

Hydrogen Ion ◽

Type I ◽

Renal Tubular

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Renal Tubular Acidosis in the Postpartum Period: A Case Report and Literature Review

Case Reports in Nephrology ◽

10.1155/2021/6693013 ◽

2021 ◽

Vol 2021 ◽

pp. 1-3

Author(s):

Carlos E. Duran ◽

Mayra Estacio ◽

Fredy Lozano ◽

Esteban Echeverri ◽

Maria Juliana Riascos ◽

...

Keyword(s):

Renal Tubular Acidosis ◽

Hydrogen Ion ◽

Ion Permeability ◽

Distal Nephron ◽

Laboratory Findings ◽

Case Presentation ◽

Ion Secretion ◽

Luminal Membrane ◽

Renal Tubular ◽

The Impact

Case Presentation. Distal renal tubular acidosis (dRTA) is characterized by impaired hydrogen ion secretion in the distal nephron resulting either from decreased net activity of the proton pump or from increased luminal membrane hydrogen ion permeability. Typical complications of dRTA include severe hypokalemia, normal anion gap metabolic acidosis, nephrolithiasis, and nephrocalcinosis. The patient is a 25-year-old woman in immediate puerperium with hypokalemia leading to paralysis, and the laboratory findings in this patients were concerning for dRTA. It is rare to encounter this entity during pregnancy, and the impact of this pathology is unknown.

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On the mechanism of impaired distal acidification in hyperkalemic renal tubular acidosis: evaluation with amiloride and bumetanide.

Journal of the American Society of Nephrology ◽

10.1681/asn.v34953 ◽

1992 ◽

Vol 3 (4) ◽

pp. 953-964

Author(s):

W Schlueter ◽

T Keilani ◽

M Hizon ◽

B Kaplan ◽

D C Batlle

Keyword(s):

Single Dose ◽

Renal Tubular Acidosis ◽

Hydrogen Ion ◽

Potassium Excretion ◽

Urine Ph ◽

Ion Secretion ◽

Group I ◽

Voltage Dependent ◽

Group Ii ◽

Renal Tubular

It has been postulated that a distinctive type of hyperkalemic distal renal tubular acidosis (DRTA), referred to as voltage-dependent DRTA, results from diminished potassium and hydrogen ion secretion in the distal nephron, which is due to a suboptimal voltage (lumen negative) as a result of impaired sodium reabsorption. To test for the presence of a voltage-dependent DRTA, we used amiloride (20 mg oral, single dose) and bumetanide (2 mg oral, single dose) to inhibit and to stimulate voltage-dependent potassium and hydrogen ion secretion, respectively. Eighteen patients with hyperkalemic DRTA and seven controls with a comparable degree of renal impairment were studied. Patients were subdivided in two groups on the basis of their ability to lower their urine pH during spontaneous acidosis. Patients in Group I lowered their urine pH to the level of controls (5.29 +/- 0.06 and 5.37 +/- 0.11, respectively) whereas patients in Group II could not lower their urine pH below 5.5 (6.38 +/- 0.11). Patients in Group I and Group II had a similar degree of metabolic acidosis and hyperkalemia whereas controls had neither acidosis or hyperkalemia. Most patients in Group II and all patients in Group I had low plasma aldosterone levels. The administration of amiloride resulted in an increase in urine pH and a decrease in potassium excretion in all three groups. The finding that amiloride, presumably by obliterating the transtubular voltage as a result of blockade of sodium transport, inhibited potassium excretion to about the same extent in both groups of patients and in controls argues against the existence of a voltage-dependent defect. Bumetanide produced a fall in urine pH below 5.5 and an increase in potassium excretion in controls and Group I patients. In Group II patients, bumetanide failed to elicit a fall in urine pH below 5.5 but resulted in an increase in potassium excretion similar to that seen in controls and Group I patients. These findings suggest that a derangement other than a voltage-dependent defect is responsible for the inability, characteristic of Group II patients, to lower their urine pH. It was concluded that the impairment in urinary acidification observed in patients with this subtype of hyperkalemic DRTA is due to a defect in collecting tubule hydrogen secretion that results from H+ ATPase dysfunction rather than from a voltage-dependent defect.

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