Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “ACIDOSIS, RENAL TUBULAR”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 91 records · Page 5Linked to original sources
PubMed2002

Bone histology and bone mineral density after correction of acidosis in distal renal tubular acidosis.

BACKGROUND: The association between chronic metabolic acidosis and alterations in bone cell functions has been demonstrated in vitro and in animal studies. However, the causal role of acidosis and the effects of alkaline therapy on bone histology and bone mineral density in chronic metabolic acidosis have never been systematically demonstrated in humans. This study was conducted to examine the alterations in bone mineral density and bone histology before and after correction of acidosis among patients with distal renal tubular acidosis (dRTA) METHODS: Correction of metabolic acidosis by potassium citrate was done in non-azotemic dRTA patients, 6 females and 4 males, who had never received long-term alkaline therapy before enrolling into this study. Blood chemistries, serum intact parathyroid hormone, and 24-hour urine collection for the determination of urinary calcium, phosphate, sodium, potassium, bone mineral density determination, and transiliac bone biopsy were done in all patients at baseline and after one year of potassium citrate therapy. RESULTS: Significant elevations in serum bicarbonate (16.5 +/- 3.0 vs. 24.6 +/- 2.8 mEq/L, P < 0.05) and urinary potassium excretion (35.2 +/- 7.9 vs. 55.4 +/-3.5 mEq/L, P < 0.05) were observed after potassium citrate therapy. No significant alterations in other serum and urine electrolytes were found after the therapy. Serum intact parathyroid hormone level was also significantly elevated after one year of treatment (12.8 +/- 7.3 vs. 26.2 +/- 8.7 pg/mL, P < 0.05). Bone formation rate was significantly suppressed at baseline and was normalized by the treatment (0.02 +/- 0.02 vs. 0.06 +/- 0.03 microm(3)/microm(2)/day, P < 0.05). There were non-significant elevations in trabecular bone volume, osteoblastic and osteoclastic numbers. Bone mineral densities in dRTA patients were also significantly decreased below normal values in most studied areas at baseline and were significantly elevated at the trochanter of femur (0.677 +/- 0.136 vs. 0.748 +/- 0.144 g/c m(2), P < 0.05) and total femur (0.898 +/- 0.166 vs. 0.976 +/- 0.154 g/c m(2), P < 0.05) after the treatment. CONCLUSIONS: This study demonstrates that alkaline therapy corrects abnormal bone cell function and elevates bone mineral density in dRTA patients, indicating the causal role of acidosis in the alterations of bone cell functions and reduction in bone mineral density. Parathyroid gland activity also may be involved in the adaptation of the body to chronic metabolic acidosis.

Acidosis, Renal Tubular↗
PubMed1997

5-Aminosalicylic acid-associated renal tubular acidosis with decreased renal function in Crohn's disease.

The use of 5-aminosalicylic acid (5-ASA, mesalazine) in Crohn's disease is usually well tolerated. Nevertheless, the occasional occurrence of nephrotoxic side effects has been described in several case reports. We present the case of a 34-year-old female in whom chronic use of 5-ASA may have caused renal damage which manifested with tubular acidosis, severe weight loss, shortness of breath and fatigue. For 17 years the patient has suffered from Crohn's disease. She received sulfasalazine (3 g/day) for 12 years and was treated with resin-coated mesalazine (3 g/day) for the last 72 months. Onset of weight loss of 10 kg over a 6-month period, accompanied by progressive shortness of breath and fatigue, lead to a diagnosis of metabolic acidosis and renal bicarbonate loss due to damage to the tubular epithelium. Kidney biopsy demonstrated acute interstitial nephritis which may be related to 5-ASA.

Acidosis, Renal Tubular↗
PubMed1995

[Renal tubular acidosis in the kidney transplant].

UNLABELLED: Renal tubular acidosis is a syndrome of disordered renal acidification, we have studied a group of patients transplanted. Their cases clinic patients have been analyzed with no-present infectious disease, or tubulointerstitial diseases or urinary infection, immunosuppression with prednisone and azatioprine only, no have to ingest cyclosporine and period graft superior 3 months. We haven't neither patient with proximal renal tubular acidosis. We have been reported 7 cases of distal renal tubular acidosis. All the patients have make the furosemide test. Only one case hyperkalemia renal tubular acidosis. Histologic kidney had been chronic rejection. CONCLUSION: renal tubular acidosis is not infrequent of kidney transplantation and this syndrome connect with chronic rejection.

Acidosis, Renal Tubular↗
PubMed1989

Screening renal stone formers for distal renal tubular acidosis.

A group of 110 consecutive renal stone formers were screened for distal renal tubular acidosis (RTA) using morning fasting urinary pH (mfUpH) levels followed by a short ammonium chloride loading test in patients with levels above 6.0. In 14 patients (12.7%) a renal acidification defect was noted; 13 had incomplete and 1 had complete distal RTA. Distal RTA was found particularly in recurrent stone formers (17%), and especially in those with bilateral stone disease, where a distal renal tubular acidification defect was found in 50%. We have been unable to differentiate primary from secondary RTA in renal stone formers. Regardless of whether the acidification defect is primary or secondary to stone formation, however, all renal stone formers with distal RTA can expect to benefit from prophylactic alkaline therapy and it is recommended that the screening procedure, which is easy to use in daily clinical practice, is applied to all stone formers and not restricted to patients with recurrent stone disease.

Acidosis, Renal Tubular↗
PubMedDate not supplied

Failure to thrive in children with primary distal type renal tubular acidosis.

Primary distal type renal tubular acidosis (RTA-type1) results from defects of distal renal tubules in urinary acidification. In attempt to evaluate the clinical features, growth and outcome of primary distal type RTA in Taiwan, we retrospectively studied 28 patients (16 males and 12 females) of primary distal type RTA in our hospital in the past 13 years. The mean age at diagnosis was 2 years and 6.8 months old. Hematuria was found in 5 out of 25 cases (20%). Nephrocalcinosis was found in 5 out of 21 cases (23.8%). The mean value of Uca/Ucr was 0.313 +/- 0.067 in those older than 2 years and 0.262 +/- 0.152 in those younger than 2 years. Rickets was suspected in only one child by radiologic study. At initial diagnosis, the mean bone age was delayed for 16 months. The older the patient was, the more delayed was the bone age. The mean value of height was -2.81 standard deviation score (SDS); the mean value of body weight was -2.44 SDS; and the mean value of growth velocity in height was -2.62 SDS. After alkali therapy given from 8.5 months to 5 years and 7 months, improvement was found in height up to -1.69SDS, in body weight up to -1.10SDS, and in height velocity up to 1.06SDS.

Acidosis, Renal Tubular↗
PubMed1982

Acquired distal renal tubular acidosis in man.

Distal renal tubular acidosis (dRTA) may complicate renal transplantation, liver cirrhosis, and obstructive uropathy. Indeed, its occurrence may be an early clue to an episode of rejection of the graft or to obstructive uropathy. The mechanism in most patients with dRTA is impaired distal secretion of protons. In some patients, however, back leak of protons from tubular lumen to blood may abolish distal tubular ability to maintain urine to blood proton gradients. In patients with obstructive uropathy the spectrum of tubular acidosis is widened by the occurrence of additional defects in tubular secretion of potassium and impairment of hydrogen ion secretion secondary to hypoaldosteronism. Hyperkalemia is also seen in "voltage dependent" states such as following the administration of lithium and amiloride. Hyperkalemia per se is conducive to acidosis by a combination of extrarenal and several intrarenal mechanisms.

Acidosis, Renal Tubular↗
PubMed1993

Pathophysiology of incomplete renal tubular acidosis in recurrent renal stone formers: evidence of disturbed calcium, bone and citrate metabolism.

Urinary acidification, bone metabolism and urinary excretion of calcium and citrate were evaluated in 10 recurrent stone formers with incomplete renal tubular acidosis (iRTA), 10 recurrent stone formers with normal urinary acidification (NUA) and 10 normal controls (NC). Patients with iRTA had lower plasma standard bicarbonate after fasting (P < 0.01) and lower urinary excretion of titratable acid (P < 0.05) and citrate (P < 0.01) compared with NUA patients and NC, and higher urinary excretion of ammonia (P < 0.05) compared with NC (P < 0.05). Hypercalciuria was found in 6 of 10 patients with iRTA compared with 3 of 10 with NUA, and 0 of 10 NC. The citrate/calcium ratio in urine was significantly reduced in iRTA compared with the value in NUA (P < 0.01), and in NUA compared with NC (P < 0.05). Biochemical markers of bone formation (serum osteocalcin) and bone resorption (urinary hydroxyproline) were significantly increased in iRTA compared with NUA and NC (P < 0.01), indicating increased bone turnover in stone formers with iRTA. Stone formers with iRTA thus presented with disturbed calcium, bone and citrate metabolism--the same metabolic abnormalities which characterize classic type 1 RTA. Mild non-carbonic acidosis during fasting may be a pathophysilogical factor of both nephrolithiasis and disturbed bone metabolism in stone formers with iRTA.

Acid-Base Equilibrium↗
PubMed1980

Renal tubular acidosis: mechanisms and management.

Renal tubular acidosis is not one entity but several. Even though all its forms are characterized by the kidney's inability to excrete an appropriately acid urine, the mechanism of the defect, its laboratory and clinical manifestations, and its management vary considerably. One type can cause disabling complications in various organ systems, while another is generally asymptomatic. Differential diagnosis is straightforward, and treatment effective.

Acidosis, Renal Tubular↗
PubMed1990

Reversible low-molecular-weight proteinuria in patients with distal renal tubular acidosis.

Four patients with untreated renal tubular acidosis had a urinary excretion of low-molecular-weight (LMW) proteins which was restored to normal by alkali therapy. Hypokalaemic proximal tubular damage in untreated patients with distal renal tubular acidosis is believed to be the cause of LMW proteinuria. An examination of urinary excretion of LMW proteins is useful for determining hypokalaemic proximal tubular dysfunction, as well as the efficiency of alkali therapy.

Acetylglucosaminidase↗
PubMed2003

Non-polarized targeting of AE1 causes autosomal dominant distal renal tubular acidosis.

Autosomal dominant distal renal tubular acidosis (ddRTA) is caused by mutations in SLC4A1, which encodes the polytopic chloride-bicarbonate exchanger AE1 that is normally expressed at the basolateral surface of alpha-intercalated cells in the distal nephron. Here we report that, in contrast with many disorders in which mutant membrane proteins are retained intracellularly and degraded, ddRTA can result from aberrant targeting of AE1 to the apical surface.

Acidosis, Renal Tubular↗
PubMed1984

Renal tubular acidosis type 4 in neonatal unilateral kidney diseases.

Three neonates, two with unilateral renal vein thrombosis and one with unilateral dysplastic kidney, developed type 4 renal tubular acidosis, manifested by nonazotemic hyperkalemic metabolic acidosis with alkaline urine pH and reduced potassium excretion. Normal plasma concentrations of sodium, aldosterone, and renin activity, together with normal renal fractional excretion of sodium, supported the diagnosis of renal tubular acidosis type 4, subtype 5. Arginine HCl loading studies showed that despite their ability to bring the urine pH to less than 5.8, net acid excretion was inadequate relative to the corresponding plasma bicarbonate concentration. Treatment with oral bicarbonate resulted in sustained normalization of blood acid-base status and accelerated linear growth in the first two infants, in whom spontaneous recovery occurred by ages 8 and 15 months, respectively. At that time, the affected kidneys were extremely small with distorted collecting systems; the contralateral kidneys showed compensatory hypertrophy. In the third infant, persistent acidosis and growth failure resulted from medical noncompliance; the removal of the dysplastic kidney at 7 months of age was followed by the return to normal blood acid-base status and normalized tubular hydrogen and potassium excretion. We conclude that neonatal unilateral kidney disease can result in renal tubular subtype 5. Spontaneous recovery can be expected, presumably because of " autonephrectomy " of the affected kidney plus the compensatory hypertrophy of the contralateral kidney.

Acidosis, Renal Tubular↗
PubMed2002

Impaired trafficking of human kidney anion exchanger (kAE1) caused by hetero-oligomer formation with a truncated mutant associated with distal renal tubular acidosis.

Autosomal dominant distal renal tubular acidosis (dRTA) has been associated with several mutations in the anion exchanger AE1 gene. The effect of an 11-amino-acid C-terminal dRTA truncation mutation (901 stop) on the expression of kidney AE1 (kAE1) and erythroid AE1 was examined in transiently transfected HEK-293 cells. Unlike the wild-type proteins, kAE1 901 stop and AE1 901 stop mutants exhibited impaired trafficking from the endoplasmic reticulum to the plasma membrane as determined by immunolocalization, cell-surface biotinylation, oligosaccharide processing and pulse-chase experiments. The 901 stop mutants were able to bind to an inhibitor affinity resin, suggesting that these mutant membrane proteins were not grossly misfolded. Co-expression of wild-type and mutant kAE1 or AE1 resulted in intracellular retention of the wild-type proteins in a pre-medial Golgi compartment. This dominant negative effect was due to hetero-oligomer formation of the mutant and wild-type proteins. Intracellular retention of kAE1 in the alpha-intercalated cells of the kidney would account for the impaired acid secretion into the urine characteristic of dRTA.

4-Acetamido-4'-isothiocyanatostilbene-2,2'-disulfo↗
PubMed2005

Defective kidney anion-exchanger 1 (AE1, Band 3) trafficking in dominant distal renal tubular acidosis (dRTA).

dRTA (distal renal tubular acidosis) results from the failure of the a-intercalated cells in the distal tubule of the nephron to acidify the urine. A truncated form of AE1 (anion-exchanger 1; Band 3), kAE1 (kidney isoform of AE1), is located in the basolateral membrane of the intercalated cell. Mutations in the AE1 gene cause autosomal dominant and recessive forms of dRTA. All the dominant dRTA mutations investigated cause aberrant trafficking of kAE1, resulting in its intracellular retention or mistargeting to the apical plasma membrane. Therefore the intracellular retention of hetero-oligomers containing wild-type and dRTA mutants, or the mistargeted protein in the apical membrane neutralizing acid secretion, explains dominant dRTA. The kAE1 (Arg(901)-->stop) mutant has been studied in more detail, since the mistargeting kAE1 (Arg(901)-->stop) from the basolateral to the apical membrane is consistent with the removal of a basolateral localization signal. The C-terminal amino acids deleted by the Arg(901)-->stop mutation, contain a tyrosine motif and a type II PDZ interaction domain. The tyrosine residue (Tyr(904)), but not the PDZ domain, is critical for basolateral localization. In the absence of the N-terminus of kAE1, the C-terminus was not sufficient to localize kAE1 to the basolateral membrane. This suggests that a determinant within the kAE1 N-terminus co-operates with the C-terminus for kAE1 basolateral localization. Interestingly, Tyr(359), in the N-terminal domain, and Tyr(904) in the C-terminus of AE1 are phosphorylated in red blood cells. A potential scheme is suggested where successive phosphorylation of these residues is necessary for correct localization and recycling of kAE1 to the basolateral membrane.

Acidosis, Renal Tubular↗
PubMed2006

The human NBCe1-A mutant R881C, associated with proximal renal tubular acidosis, retains function but is mistargeted in polarized renal epithelia.

The human electrogenic renal Na-HCO(3) cotransporter (NBCe1-A; SLC4A4) is localized to the basolateral membrane of proximal tubule cells. Mutations in the SLC4A4 gene cause an autosomal recessive proximal renal tubular acidosis (pRTA), a disease characterized by impaired ability of the proximal tubule to reabsorb HCO(3)(-) from the glomerular filtrate. Other symptoms can include mental retardation and ocular abnormalities. Recently, a novel homozygous missense mutant (R881C) of NBCe1-A was reported from a patient with a severe pRTA phenotype. The mutant protein was described as having a lower than normal activity when expressed in Xenopus oocytes, despite having normal Na(+) affinity. However, without trafficking data, it is impossible to determine the molecular basis for the phenotype. In the present study, we expressed wild-type NBCe1-A (WT) and mutant NBCe1-A (R881C), tagged at the COOH terminus with enhanced green fluorescent protein (EGFP). This approach permitted semiquantification of surface expression in individual Xenopus oocytes before assay by two-electrode voltage clamp or measurements of intracellular pH. These data show that the mutation reduces the surface expression rather than the activity of the individual protein molecules. Confocal microscopy on polarized mammalian epithelial kidney cells [Madin-Darby canine kidney (MDCK)I] expressing nontagged WT or R881C demonstrates that WT is expressed at the basolateral membrane of these cells, whereas R881C is retained in the endoplasmic reticulum. In summary, the pathophysiology of pRTA caused by the R881C mutation is likely due to a deficit of NBCe1-A at the proximal tubule basolateral membrane, rather than a defect in the transport activity of individual molecules.

4,4'-Diisothiocyanostilbene-2,2'-Disulfonic Acid↗