[An experimental model of renal tubular acidosis--with special reference to distal renal tubular acidosis].
Explore the source record for details and available documents.
Acidosis, Renal Tubular↗
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.
[Renal tubular acidosis during a course of liver cirrhosis].
In a group of 23 patients suffering from liver cirrhosis, metabolic acidosis was always observed, in most cases corrected by respiratory alkalosis. In 8,6% of cases a tubular renal acidosis (type I), in 8,6% (type II) and 8,6% a loss of urinary bicarbonate without acidosis were observed.
Acidosis, Renal Tubular↗
[Renal tubular acidosis in children].
Renal tubular acidosis represents a heterogenous group of disorders with various etiologies and mechanisms. The physiopathologic basis of each type of renal tubular acidosis is reviewed, focusing on the laboratory investigations necessary to define the nature of the hyperchloremic renal tubular acidosis. Clinically, the four types of renal tubular acidosis can be associated with complications such as osteomalacia, urolithiasis and failure to thrive. Very often, the chronic administration of alkali results in normal growth and development, and greatly reduces the risk of stone formation or nephrocalcinosis.
Acid-Base Equilibrium↗
ASdult Fanconi's syndrome with renal tubular acidosis in association with renal amyloidosis: occurrence in a patient with chronic lymphocytic leukemia.
In a patient with chronic lymphocytic leukemia, multiple renal tubular defects developed in association with urinary excretion of K light chain proteins and peritubular deposits and casts of amyloid. Proximal tubular dysfunction, resembling adult Fanconi's syndrome, was suggested by an increased urinary loss of phosphate and urate and glycosuria. Renal tubular acidosis with hypokalemia and a marked impairment of the urinary concentrating mechanism were also observed.
Acidosis, Renal Tubular↗
Extensive glomerular immaturity associated with renal tubular acidosis, nephrogenic diabetes insipidus and nephrocalcinosis.
Neonatal renal failure and glomerular immaturity have been described in 1983. The present paper describes 3 cases with the same histological features. However, follow-up of the patients during 14, 18 and 4 years, respectively, showed the following: The histologic immaturity may be followed by maturation. Thus, late maturation may be a term more suitable to designate this constellation. Renal failure may not necessarily ensue, at least not during early infancy. In the 3 cases presented in this report, the histological finding is associated with renal tubular acidosis, renal diabetes insipidus and nephrocalcinosis. The association of transient glomerular immaturity (or late glomerular maturation) and renal tubular acidosis may enhance the development of nephrocalcinosis.
Acidosis, Renal Tubular↗
Renal tubular acidosis in infants: the several kinds, including bicarbonate-wasting, classic renal tubular acidosis.
In four infants with renal tubular acidosis (RTA), including three with apparently classic RTA and one with Fanconi syndrome (FS), the physiologic character of the renal acidification defect was investigated. In two of the infants with apparently classic RTA, the acidification defect was physiologically separable from that described in both adult patients and children with classic RTA (type 1 RTA) in the following ways. (a) The fractional excretion of filtered bicarbonate (C(HCO3)/C(ln)) was not trivial but substantial (6-9%), as well as relatively fixed, over a broad range of plasma bicarbonate concentrations (15-26 mmoles/liter). (b) This value of C(HCO3)/C(ln), combined with a normal or near normal glomerular filtration rate, translated to renal bicarbonate wasting (RBW). (c) RBW at normal plasma bicarbonate concentrations was the major cause of acidosis, and its magnitude was the major determinant of corrective alkali therapy (5-9 mEq/kg per day), just as in the patient with FS, who was found to have type 2 ("proximal") RTA. (d) Persistence of RBW at substantially reduced plasma bicarbonate concentrations, which did not occur in FS, accounted for the spontaneous occurrence of severe acidosis and its rapid recurrence after reduction in alkali therapy. (e) During severe acidosis the urinary pH was >7, a finding reported frequently in infants with apparently classic RTA and "alkali-resistant" acidosis but rarely in adult patients with classic RTA. Continued supplements of potassium were required to maintain normokalemia during sustained correction of acidosis with alkali therapy. Yet, in at least two of the three infants with apparently classic RTA, but in distinction from the patient with FS and other patients with type 2 RTA, fractional excretion of filtered potassium decreased when plasma bicarbonate was experimentally increased to normal values. In one of the two infants with apparently classic RTA and RBW, C(HCO3)/C(ln) and the therapeutic alkali requirement decreased concomitantly and progressively over 2 yr, but RBW continued. Renal tubular acidosis has persisted in all four patients for at least 3 yr, and in three for 4 years.
Acidosis, Renal Tubular↗
Impaired renal conservation of sodium and chloride during sustained correction of systemic acidosis in patients with type 1, classic renal tubular acidosis.
In 10 patients with classic renal tubular acidosis in whom correction of acidosis was sustained with orally administered potassium bicarbonate, renal conservation of sodium was evaluated when dietary intake of sodium was restricted to 9--13 meq/day. In five patients, renal conservation of sodium was impaired by at least one criterion of impairment. In the remaining patients, renal conservation of sodium appeared to be relatively well-maintained, but an impairment could not be excluded. In each of six patients studied during induced water diuresis, including two in whom renal conservation of sodium was not unequivocally impaired, the minimal urinary concentrations of sodium were inappropriately high and the urinary excretion rates of sodium were flow-dependent. These results provide direct evidence that an abnormality in renal transport of sodium can occur in classic renal tubular acidosis, and compel a reconsideration of the pathophysiology of disordered renal transport of sodium in this disorder. The results indicate that in at least some patients with classic renal tubular acidosis impaired renal conservation of sodium is not exclusively a reversible consequence of the renal acidification defect. These findings raise the question whether renal transport of sodium is unimpaired in any patients with classic renal tubular acidosis. In the presently studied patients, the impairment in renal conservation of sodium appeared to be in part the consequence of an impaired ability of the vasopressin-responsive segments of the distal nephron to generate and maintain appropriately steep transepithelial sodium concentration gradients.
Acid-Base Equilibrium↗
Renal tubular acidosis, hypokalemic paralysis, rhabdomyolysis, and acute renal failure--a rare presentation of Chinese herbal nephropathy.
We encountered a 66-year-old Chinese man presented with hypokalemic paralysis, rhabdomyolysis and acute renal failure after administration of mixed Chinese herbs. Proximal renal tubular acidosis and selective glucosuria were the main tubular dysfunctions. The renal failure recovered smoothly and rapidly after resuscitation and the tubular function abnormalities regained spontaneously after medicine withdrawal. It should be recognized that renal tubular acidosis with hypokalemic paralysis, rhabdomyolysis and subsequent acute renal failure may develop after taking Chinese mixed herbal medicine.
Acidosis, Renal Tubular↗
Confirmation of the ATP6B1 gene as responsible for distal renal tubular acidosis.
Primary distal renal tubular acidosis (dRTA) type I is a hereditary renal tubular disorder, which is characterized by impaired renal acid secretion resulting in metabolic acidosis. Clinical symptoms are nephrocalcinosis, nephrolithiasis, osteomalacia, and growth retardation. Biochemical alterations consist of hyperchloremic metabolic acidosis, hypokalemia with muscle weakness, hypercalciuria, and inappropriately raised urinary pH. Autosomal dominant and rare forms of recessive dRTA are known to be caused by mutations in the gene for the anion exchanger AE1. In order to identify a gene responsible for recessive dRTA, we performed a total genome scan with 303 polymorphic microsatellite markers in six consanguineous families with recessive dRTA from Turkey. In four of these there was an association with sensorineural deafness. The total genome scan yielded regions of homozygosity by descent in all six families on chromosomes 1, 2, and 10 as positional candidate region. In one of these regions the gene ATP6B1for the ss1 subunit of the vacuolar H(+)-ATPase is localized, which has recently been identified as causative for recessive dRTA with sensorineural deafness. Therefore, we conducted mutational analysis in 15 families and identified potential loss-of-function mutations in ATP6B1in 8. We thus confirmed that defects in this gene are responsible for recessive dRTA with sensorineural deafness.
Acidosis, Renal Tubular↗
Renal cyst formation as a complication of primary distal renal tubular acidosis.
Morphologic studies using renal sonography and CT scanning were performed in 6 patients with primary distal renal tubular acidosis who were followed for 6 to 18 years. Nephrocalcinosis and renal cysts were identified in all patients. Multiple bilateral renal cysts were detected in 3 patients, and unilateral single or several renal cysts were detected in 3 patients. Size and number of the renal cysts in 1 patient did not change over 5 years of alkali therapy. Although the precise mechanism for renal cyst formation has not yet been established, renal cysts may be a common complication of primary distal renal tubular acidosis.
Acidosis, Renal Tubular↗
Transient renal tubular acidosis in pregnancy.
Renal tubular acidosis in pregnancy is a very rare disorder. Most cases are either inherited or secondary to maternal disease or ingestion of toxic chemicals. We report a 22-year-old woman, previously healthy, who presented at 27 weeks of gestation with preterm labor. Investigation revealed renal tubular acidosis with no obvious etiology. Labor was stopped with various tocolytic drugs and her electrolyte imbalance was corrected. She was delivered at 36 weeks, by cesarean for a nonreassuring fetal heart tracing, of an appropriate-for-gestational-age infant weighing 2905 g. Evaluation 3 and 6 months postpartum revealed gradual, but complete resolution of the acidosis and electrolyte abnormality. The infant is now 7 months old, is growing normally with normal electrolytes, and with no evidence of acidosis.
Acidosis, Renal Tubular↗
[Osteopenia and renal calcification in a 4.5 year old child with primary distal renal tubular acidosis treated for idiopathic renal hypercalciuria].
We present a case of a 4.5 years old boy suffering from hypercalciuria caused by a not diagnosed distal renal tubular acidosis. In the age of 2.5 years, after a banal infection the routine analysis showed a presence of numerous calcium phosphates in urine. Other diagnostic procedures showed: hypercalciuria, hyperphosphaturia, rather high calcemia and high values of UCa/cr and UPO4/cr ratios. HCO3 in serum 21.2 mmol/l, pH of urine 7.0. Kidneys and urinary tract-usg normal. These results induced the family doctor to make the diagnosis: idiopathic renal hypercalciuria. He advised the therapy with hydrochlorothiazide and limitations of calcium and vitamins D3 oral supply. This decision caused an illusory positive effect: decreased the UCa/cr ratio (to 0.96 mmol/mmol) without any reduction of calcemia. After a period of 12 months the UCa/cr ratio increased up to 1.31 and calcification of renal pyramids appeared. We diagnosed the distal renal tubular acidosis (some medical informations suggested the essential distal renal tubular acidosis) and osteopenia (DXA BMD L1-L4 below -1 s.d.). The therapy with NaHCO3 (about 2.6 mmol/kg) normalized the levels of HCO3a and calcium in serum, decreased the UCa/cr ratio to values 0.09-0.16 mmol/mmol.
Acidosis, Renal Tubular↗
Disequilibrium pH and bicarbonate reabsorption: relevance to the pathogenesis of distal renal tubular acidosis.
An augmented renal capacity to reabsorb bicarbonate (RHCO3) has been noted in patients with distal renal tubular acidosis (dRTA), and construed as evidence that the basic defect in dRTA is abnormal distal tubular permeability. According to this interpretation, the absence of a disequilibrium pH due to a back-leak of H2C03 permits increased distal H+ secretion and results in an increased RHCO3. To test this assumption, we have evaluated the effect of acute elimination of the disequilibrium pH by carbonic anhydrase infusion. The results establish that this maneuver doses not cause a rise in RHCO3. Thus, the elevated value of RHC3 described in dRTA cannot be the consequence of increased back-diffusion of H2CO3 and is more likely due to coexisting extracellular volume depletion and/or postassium deficiency.
Acidosis, Renal Tubular↗
[Distal tubular renal acidosis associated with hyperglobulinemic purpura and Sjõgren's syndrome].
A 35-year-old female with a diagnosis of Waldenström's benign hypergammaglobulinemic purpura developed bilateral renal stones during the course of her disease. Evaluation disclosed type I distal tubular renal acidosis. In addition, the patient developed Sjögren's syndrome seven years later. The etiology and pathogenesis of renal tubular acidosis secondary to autoimmune disease are reviewed, and the exceptional occurrence of the three conditions in a single patient is commented.
Acidosis, Renal Tubular↗
The importance of renal ammonia metabolism to whole body acid-base balance: a reanalysis of the pathophysiology of renal tubular acidosis.
Traditionally, the renal collecting duct has been assigned the dual role of (1) secreting protons derived from dietary metabolism to form luminal NH4+ and titratable acid and (2) generating new HCO3-. This view has recently been challenged. According to current concepts, whole body proton balance is maintained predominantly by the lungs which excrete protons derived from dietary metabolism as the acid anhydride CO2. In the process of excreting CO2, HCO3- is also lost from the body. It is the function of the kidney to generate new HCO3- to replenish this loss. The major site of new HCO3- generation is the proximal tubule rather than the collecting duct. New HCO3- is generated predominantly via the metabolism of organic anions, i.e. alpha-ketoglutarate, citrate, lactate, fatty acids. In the process of generating alpha-ketoglutarate from glutamine, NH4+ is formed. Under normal acid-base conditions, 50% of the NH4+ produced is excreted in the urine, and the remaining 50% is delivered to the renal veins. NH4+ delivered to the renal veins consumes HCO3- during ureagenesis. In the discussion which follows, these new concepts are reviewed and applied to an analysis of the pathophysiology of renal tubular acidosis.
Acid-Base Equilibrium↗
Hypokalemic paralysis associated with renal tubular acidosis.
Patients with renal tubular acidosis may show hypokalemic paralysis. We report a case in which the symptoms of hypokalemia and the onset of paralysis were initially mistaken for the Guillain-Barré syndrome.
Acidosis, Renal Tubular↗
Incomplete renal tubular acidosis and bone mineral density: a population survey in an area of endemic renal tubular acidosis.
BACKGROUND: 'Primary' osteoporosis has been associated with a high incidence of a renal acidification defect, incomplete renal tubular acidosis (iRTA). An acid loading test, to exclude the defect, has been recommended for inclusion in the work-up of osteoporosis. However, there is no community-based study to confirm its utility. METHOD: A community-based survey was conducted in the Khon Kaen province, Thailand, between January and June, 2000. We randomly enrolled 361 apparently healthy adults, 146 men and 215 women, in this study. The bone mineral densities (BMDs) of the spine and femur were determined in all subjects. The diagnosis of iRTA was based on: normal serum electrolytes and one or both of first morning urinary pH >5.5 or the failure of an acid loading test to decrease it to >5.5. Dietary diaries, serum electrolyte tests and 24 h urine collections were obtained from all iRTA subjects. RESULTS: There were 23 (6.4%) iRTA subjects in the population studied. The age, height, weight and calcium intake were comparable between iRTA and normal subjects, as were the BMDs of spine and femur. There was no difference between the two groups in the distributions of BMD with age for either area. Multiple regression analyses of the studied population demonstrated that age, body weight, duration of menopause and gender (only for the femoral neck) were independent variables that affected BMD. CONCLUSION: Incomplete distal renal tubular acidosis alone was not associated with lower bone mass in this cohort. It may nevertheless be valuable to monitor serum electrolytes and BMD in patients with iRTA due to their tendency to develop intermittent metabolic acidosis.
Acidosis, Renal Tubular↗
Renal tubular acidosis.
The term renal tubular acidosis (RTA) is applied to a group of transport defects in the reabsorption of bicarbonate (HCO3-), the excretion of hydrogen ions, or both. On clinical and pathophysiological grounds, RTA can be separated into three main types: distal RTA (type 1), proximal RTA (type 2) and hyperkalaemic RTA (type 4). Some patients present combined types of proximal and distal RTA or of hyperkalaemic and distal RTA. Diagnosis of RTA should be suspected when a patient presents a normal plasma anion gap, and hyperchloraemic metabolic acidosis. A normal plasma anion gap (Na(+)-[Cl- + HCO3-] = 8-16 mEq/l) reflects loss of HCO3- from the extracellular fluid via the gastro-intestinal tract or the kidney, dilution of extracellular buffer or administration of hydrochloric acid (HCl) or its precursors. Distinction of RTA from other disorders is greatly facilitated by the study of the urine anion gap (Na+ + K+ - Cl-). This index estimates the urinary concentration of ammonium in a patient with hyperchloraemic metabolic acidosis. A negative urine anion gap (Cl- much greater than Na+ + K+) suggests the presence of gastro-intestinal or renal loss of HCO3-, while a positive urine anion gap (Cl- less than Na+ + K+) is indicative of a distal acidification defect. Determination of plasma potassium, of urine pH at low plasma HCO3- concentration, and of urine PCO2 and fractional excretion of HCO3- at normal plasma HCO3- concentration permits the differentiation between the various types of RTA.
Acidosis, Renal Tubular↗