El regulador de transmembrana de fibrosis quística (CFTR) disfuncional y sus efectos extrapulmonares / The dysfunction of transmembrane regulator in cystic fibrosis (CFTR) and its extrapulmonary effects

El daño del regulador de transmembrana de fibrosis quística (CFTR) puede causar una enfermedad grave fuera de los pulmones. El canal de cloruro (Cl-) ha sido el más estudiado, sin embargo, el bicarbonato (HCO3 -) tiene un rol muy importante en el comportamiento de las secreciones y la inflamación secundaria. El hecho de que CFTR funcione no sólo como un canal de Cl- sino también de HCO3- es un campo para la investigación y el desarrollo de fármacos para pacientes con daño genético o adquirido, este último frecuente en la población general. Algunos moduladores de CFTR pueden tener un beneficio terapéutico en el tratamiento de pancreatitis en ambas situaciones. La disfunción del CFTR a nivel renal puede resultar excepcionalmente en alcalosis metabólica y reducción del impulso ventilatorio. Hasta la fecha no está claro cuales serian sus efectos en los sistemas gastrointestinal y hepatobiliar.

Transmembrane regulator in cystic fibrosis (CFTR) can cause severe disease outside of the lungs. The chloride channel (Cl-) has been the most studied, however bicarbonate (HCO3 -) has a very important role in the behavior of secretions and secondary inflammation. The fact that CFTR works not only as a Cl- channel but also as an HCO3- channel is a field for research and development of drugs for patients with genetic or acquired damage, the latter frequent in the general population. Some CFTR modulators may have a therapeutic benefit in the treatment of pancreatitis in both situations. CFTR dysfunction at the renal level can exceptionally result in metabolic alkalosis and reduced ventilatory drive. To date it is not clear what its effects on the gastrointestinal and hepatobiliary systems would be.

Regulation of kidney on potassium balance and its clinical significance / 生理学报

Virtually all of the dietary potassium intake is absorbed in the intestine, over 90% of which is excreted by the kidneys regarded as the most important organ of potassium excretion in the body. The renal excretion of potassium results primarily from the secretion of potassium by the principal cells in the aldosterone-sensitive distal nephron (ASDN), which is coupled to the reabsorption of Na+ by the epithelial Na+ channel (ENaC) located at the apical membrane of principal cells. When Na+ is transferred from the lumen into the cell by ENaC, the negativity in the lumen is relatively increased. K+ efflux, H+ efflux, and Cl- influx are the 3 pathways that respond to Na+ influx, that is, all these 3 pathways are coupled to Na+ influx. In general, Na+ influx is equal to the sum of K+ efflux, H+ efflux, and Cl- influx. Therefore, any alteration in Na+ influx, H+ efflux, or Cl- influx can affect K+ efflux, thereby affecting the renal K+ excretion. Firstly, Na+ influx is affected by the expression level of ENaC, which is mainly regulated by the aldosterone-mineralocorticoid receptor (MR) pathway. ENaC gain-of-function mutations (Liddle syndrome, also known as pseudohyperaldosteronism), MR gain-of-function mutations (Geller syndrome), increased aldosterone levels (primary/secondary hyperaldosteronism), and increased cortisol (Cushing syndrome) or deoxycorticosterone (hypercortisolism) which also activate MR, can lead to up-regulation of ENaC expression, and increased Na+ reabsorption, K+ excretion, as well as H+ excretion, clinically manifested as hypertension, hypokalemia and alkalosis. Conversely, ENaC inactivating mutations (pseudohypoaldosteronism type 1b), MR inactivating mutations (pseudohypoaldosteronism type 1a), or decreased aldosterone levels (hypoaldosteronism) can cause decreased reabsorption of Na+ and decreased excretion of both K+ and H+, clinically manifested as hypotension, hyperkalemia, and acidosis. The ENaC inhibitors amiloride and Triamterene can cause manifestations resembling pseudohypoaldosteronism type 1b; MR antagonist spironolactone causes manifestations similar to pseudohypoaldosteronism type 1a. Secondly, Na+ influx is regulated by the distal delivery of water and sodium. Therefore, when loss-of-function mutations in Na+-K+-2Cl- cotransporter (NKCC) expressed in the thick ascending limb of the loop and in Na+-Cl- cotransporter (NCC) expressed in the distal convoluted tubule (Bartter syndrome and Gitelman syndrome, respectively) occur, the distal delivery of water and sodium increases, followed by an increase in the reabsorption of Na+ by ENaC at the collecting duct, as well as increased excretion of K+ and H+, clinically manifested as hypokalemia and alkalosis. Loop diuretics acting as NKCC inhibitors and thiazide diuretics acting as NCC inhibitors can cause manifestations resembling Bartter syndrome and Gitelman syndrome, respectively. Conversely, when the distal delivery of water and sodium is reduced (e.g., Gordon syndrome, also known as pseudohypoaldosteronism type 2), it is manifested as hypertension, hyperkalemia, and acidosis. Finally, when the distal delivery of non-chloride anions increases (e.g., proximal renal tubular acidosis and congenital chloride-losing diarrhea), the influx of Cl- in the collecting duct decreases; or when the excretion of hydrogen ions by collecting duct intercalated cells is impaired (e.g., distal renal tubular acidosis), the efflux of H+ decreases. Both above conditions can lead to increased K+ secretion and hypokalemia. In this review, we focus on the regulatory mechanisms of renal potassium excretion and the corresponding diseases arising from dysregulation.

Reninoma: a rare cause of curable hypertension / 소아과

The most common type of refractory hypertension found in children is secondary hypertension, which is a potentially curable disease. Reninoma, a renin-secreting juxtaglomerular cell tumor, is a rare cause of severe hypertension that is usually diagnosed in adolescents and young adults. Surgical resection of the tumor completely cures the hypertension of patients with reninoma. The typical clinical presentation of reninoma includes hypokalemia, metabolic alkalosis, and features secondary to the increased activation of the renin-angiotensin system without renal artery stenosis. We report a case of reninoma in a female adolescent with a typical clinical presentation, in which surgical removal of the tumor completely cured hypertension. We discuss here the clinical features, imaging studies, and immunohistochemical examination of the tumor used to establish the diagnosis of reninoma and for the management of the condition.

Situación del estado ácido-base de pacientes incidentes a la emergencia de Medicina de un hospital nacional de Lima Perú y su asociación a variables clínicas / Situation of the acid-base disorders and their association with clinical variables in incident patients at the emergency room in a national hospital in Lima, Peru

Objetivos: Determinar la frecuencia de trastornos del estado ácido-base de pacientes admitidos al Departamento de Emergencia de un hospital general de Lima-Perú y su asociación con enfermedades prevalentes. Material y métodos: Estudio transversal descriptivo y analítico cuyo tamaño de muestra calculado fue en 108 pacientes a quienes el médico tratante solicitó estudio de gasometría arterial. La muestra fue obtenida por saturación hasta alcanzar el tamaño mínimo calculado. Resultados: El disturbio ácido-base más frecuentemente hallado fue el trastorno mixto de la acidosis metabólica asociado con la alcalosis respiratoria (50% casos) coexistiendo en pacientes con disfunción renal aguda o crónica y shock, seguido del disturbio único de alcalosis respiratoria (26,2% casos) asociada a enfermedad respiratoria y gastrointestinal. Conclusiones: Los trastornos mixtos de acidosis metabólica con alcalosis respiratoria son altamente relevantes y la alcalosis respiratoria es el fenómeno puro más frecuente. (AU)

Objectives: To determine the frequency of acid-base disorders and their association with prevalent diseases in patients admitted to the emergency department of a national hospital in Lima. Methods: Cross-sectional study with a sample size of 108 patients in whom the treating physician requested arterial blood gases determination. The sample was attained by saturation until reaching the targeted sample size. Results: The most common acid-base disorder was mixed metabolic acidosis (50%) co-existing in patients with acute or chronic renal dysfunction and shock, followed by respiratory alkalosis (26.2%) associated to respiratory and gastro-intestinal disorders. Conclusions: Mixed metabolic acidosis and respiratory alkalosis are the most frequent acid-base abnormalities observed in this setting, respiratory alkalosis is the most common single acid-base disorder found. (AU)

Clinical characterization and diagnosis of cystic fibrosis through exome sequencing in Chinese infants with Bartter-syndrome-like hypokalemia alkalosis / 医学前沿

Cystic fibrosis (CF) is a fatal autosomal-recessive disease caused by mutations in the CF transmembrane conductance regulator (CFTR) gene. CF is characterized by recurrent pulmonary infection with obstructive pulmonary disease. CF is common in the Caucasian population but is rare in the Chinese population. The symptoms of early-stage CF are often untypical and may sometimes manifest as Bartter syndrome (BS)-like hypokalemic alkalosis. Therefore, the ability of doctors to differentiate CF from BS-like hypokalemic alkalosis in Chinese infants is a great challenge in the timely and accurate diagnosis of CF. In China, sporadic CF has not been diagnosed in children younger than three years of age to date. Three infants, who were initially admitted to our hospital over the period of June 2013 to September 2014 with BS-like hypokalemic alkalosis, were diagnosed with CF through exome sequencing and sweat chloride measurement. The compound heterozygous mutations of the CFTR gene were detected in two infants, and a homozygous missense mutation was found in one infant. Among the six identified mutations, two are novel point mutations (c.1526G > C and c.3062C > T) that are possibly pathogenic. The three infants are the youngest Chinese patients to have been diagnosed with sporadic CF at a very early stage. Follow-up examination showed that all of the cases remained symptom-free after early intervention, indicating the potential benefit of very early diagnosis and timely intervention in children with CF. Our results demonstrate the necessity of distinguishing CF from BS in Chinese infants with hypokalemic alkalosis and the significant diagnostic value of powerful exome sequencing for rare genetic diseases. Furthermore, our findings expand the CFTR mutation spectrum associated with CF.

Approach to the Patient with Metabolic Alkalosis Accompanied by Hypokalemia / 대한내과학회지

No abstract available.

Alterações hemogasométricas em equinos submetidos à distensão do cólon menor / Blood gas alterations in horses subjected to small colon distention

O objetivo do presente estudo foi avaliar a hemogasometria venosa de equinos com lesões isquêmicas induzidas experimentalmente no cólon menor. Foram utilizados oito equinos sadios, com idades entre cinco e oito anos, sem raça definida. Os animais foram submetidos à celiotomia e a quatro horas de obstrução intraluminal do cólon menor. Foram realizadas coletas de amostras de sangue imediatamente antes da indução anestésica (T0), no momento em que a anestesia foi estabilizada (T1), quatro horas após a obstrução intraluminal (T4), e, durante o pós-cirúrgico, as coletas foram realizadas em intervalos de 12 horas até completar 72 horas (T16, T28, T40, T52, T64 e T76). Notou-se em T4 alcalose metabólica, com compensação respiratória por meio da hipoventilação. Esse quadro de alcalose foi brando e transitório, retornando os valores normais para a espécie em T16, com 12 horas de desobstrução intestinal.(AU)

The objective of this study was to evaluate the blood gas analysis of venous blood of horses with experimentally induced ischemic lesions on the lower colon. Eight healthy horses were used, with ages between five and eight years, mixed breed. The animals were subjected to celiotomy and four hours of lower colonic intraluminal obstruction. The harvests were made with the blood samples immediately before induction of anesthesia (T0), when the anesthesia was stabilized (T1), 4 hours after the intraluminal obstruction (T4) and during postsurgical times were performed at intervals of 12 hours to complete 72 hours (T16, T28, T40, T52, T64 and T76). The occurrence of metabolic alkalosis on T4 with respiratory compensation by hypoventilation was noted, this alkalosis period was bland and transient, returning the normal values for the specie on T16, 12 hours after the intestinal obstruction.(AU)

Alcalose metabólica induzida por bicarbonato de sódio: mecanismos de ação, dose utilizada e efeitos sobre o desempenho em ciclismo de alta intensidade / Induced metabolic alkalosis by sodium bicarbonate: action mechanisms, dose and effects on highintensity cycling performance

A relação entre a alcalose metabólica e o desempenho esportivo tem sido investigada através de anipulações do pH sanguíneo. Entre as formas de manipulação do pH, o bicarbonato de sódio (NaHCO3) é o componente químico mais utilizado quando se pretende induzir um estado de alcalose sanguínea previamente ao exercício. Embora os benefícios do NaHCO3 no desempenho tenham sido amplamente demonstrados em exercícios intermitentes de alta intensidade, não há um consenso na literatura e pouco ainda é conhecido quanto aos efeitos do NaHCO3 em exercícios contínuos de ciclismo de alta intensidade. Nesse sentido, foram abordados na presente revisão os principais aspectos envolvidos na ingestão aguda e crônica de NaHCO3, enfatizando os mecanismos de ação dessa substância, especificações acerca da dose utilizada e seus efeitos sobre o desempenho em ciclismo de alta intensidade. Os resultados dos estudos apresentados na presente revisão revelam que a ingestão aguda de 0,3 g∙kg-1 de massa corporal (MC) de NaHCO3 é eficaz em melhorar o desempenho em eventos de alta intensidade se consumido em torno de 90 minutos antes do exercício. Para a ingestão crônica, uma dose de 0,5 g∙kg-1 ∙dia1 de MC durante 5-6 dias seria benéfica para o exercício de alta intensidade. Esses seriam os limites em ambos os protocolos para induzir um estado de alcalose metabólica e posteriormente melhorar o desempenho sem promover ou atenuando qualquer sintoma relacionado à sensações de desconforto gastrointestinal. Dessa forma, ambas as formas de ingestão de NaHCO3, aguda e/ou crônica, parecem melhorar o desempenho durante o ciclismo de alta intensidade realizados de modo contínuo, enfatizando a importância da suplementação de NaHCO3 como um recurso ergogênico. Porém, pesquisas adicionais utilizando protocolos de ingestão crônica e testando seus efeitos sobre o desempenho em provas mais prolongadas são requeridas devido ao reduzido número de investigações e o potencial efeito ergogênico dessa substância...(AU)

The relationship between metabolic alkalosis and exercise performance has been investigated through manipulation of the blood and muscle pH. Among the forms of pH manipulation, the sodium bicarbonate (NaHCO3) is the most used chemical component when is intentioned to induce a blood alkalosis state prior to exercise. While the benefits of NaHCO3 in performance have been widely demonstrated in high-intensity intermittent exercise, there is no consensus in the literature and little is known about the effects of NaHCO3 in continuous high-intensity cycling exercise. Thus, it was addressed in this present review the main aspects involved in acute and chronic NaHCO3 ingestion, giving a focus to the action mechanisms of this substance, specifications about the used dose and their effects on highintensity cycling performance. The results of the present review show that acute ingestion of 0.3 g∙kg-1 of body mass (BM) of NaHCO3 is effective in improving performance in high-intensity events if this substance is consumed in about 90 minutes prior to exercise. For chronic ingestion, a dose of 0.5 g∙kg1 ∙day-1 BM during 5-6 days should be beneficial for the high-intensity exercise. For both protocols these would be the limits to induce a metabolic alkalosis state and further improve the performance without promoting or attenuating any symptoms related to the gastrointestinal discomfort sensations. Thus, both acute and/or chronic NaHCO3 ingestion seem to improve performance during high-intensity cycling performed in a continuous mode, emphasizing the importance of NaHCO3 supplementation as an ergogenic aid. However, further research using chronic ingestion of protocols and testing their effects on performance in more prolonged tests are required due to the small number of studies and the potential ergogenic effect of this substance...(AU)

The impact of high serum bicarbonate levels on mortality in hemodialysis patients

BACKGROUND/AIMS: The optimal serum bicarbonate level is controversial for patients who are undergoing hemodialysis (HD). In this study, we analyzed the impact of serum bicarbonate levels on mortality among HD patients. METHODS: Prevalent HD patients were selected from the Clinical Research Center registry for End Stage Renal Disease cohort in Korea. Patients were categorized into quartiles according to their total carbon dioxide (tCO₂) levels: quartile 1, a tCO₂ of < 19.4 mEq/L; quartile 2, a tCO₂ of 19.4 to 21.5 mEq/L; quartile 3, a tCO₂ of 21.6 to 23.9 mEq/L; and quartile 4, a tCO₂ of ≥ 24 mEq/L. Cox regression analysis was used to calculate the adjusted hazard ratio (HR) and confidence interval (CI) for mortality. RESULTS: We included 1,159 prevalent HD patients, with a median follow-up period of 37 months. Kaplan-Meier analysis revealed that the all-cause mortality was significantly higher in patients from quartile 4, compared to those from the other quartiles (p = 0.009, log-rank test). The multivariate Cox proportional hazard model revealed that patients from quartile 4 had significantly higher risk of mortality than those from quartile 1, 2 and 3, after adjusting for the clinical variables in model 1 (HR, 1.99; 95% CI, 1.15 to 3.45; p = 0.01) and model 2 (HR, 1.82; 95% CI, 1.03 to 3.22; p = 0.04). CONCLUSIONS: Our data indicate that high serum bicarbonate levels (a tCO₂ of ≥ 24 mEq/L) were associated with increased mortality among prevalent HD patients. Further effort might be necessary in finding the cause and correcting metabolic alkalosis in the chronic HD patients with high serum bicarbonate levels.

Rheumatoid arthritis accompanied by Gitelman syndrome / 영남의대학술지

Gitelman syndrome is a condition caused by a mutation of the thiazide sensitive Na-Cl cotransporter gene on the distal convoluted tubule. It results in a variety of clinical features, including hypokalemia, hypomagnesemia, hypocalciuria, and metabolic alkalosis. It is often diagnosed in asymptomatic adults presented with unexplained hypokalemia; however, it is sometimes associated with muscular cramps, numbness, fatigue, weakness, or paralysis. We experienced a case of rheumatoid arthritis accompanied by Gitelman syndrome, presented with hand tremor. We diagnosed her using renal clearance study and genetic analysis. Here, we report our experiences regarding this case along with a literature review.

Cambios en el pH sanguíneo en los pacientes críticos durante la hospitalización en Cuidados Intensivos / Changes in blood pH in critical patients during Hospitalization in Care Intensive

Objetivo: Determinar los cambios que se desarrollan en el pH sanguíneo de pacientes críticos en Cuidados Intensivos, según el tipo de trastorno. Diseño: Estudio cuantitativo, de observación, analítico, de tipo cohorte retrospectivo. Ámbito: Unidad de Cuidados Intensivos polivalente. Participantes, intervenciones y variables: 753 pacientes con pH normal, después de excluir a aquellos con registros insuficientes o antecedente de acidosis tubular renal. Se analizó la información de la base de datos clínica durante 21 meses. Mediante un análisis de supervivencia, se observó el cambio del pH, estratificando grupos de acuerdo con la alteración primaria y, luego, por morbilidad de ingreso. Se estimó la diferencia entre los grupos mediante la prueba del rango logarítmico. Los factores determinantes de acidemia metabólica se evaluaron mediante regresión de Cox. Resultados: Se evaluó a 753 pacientes (mediana de la edad 60 años [RIQ: 40- 71]). La mediana de estancia fue de 8 días (RIQ: 6-13). El 42% tenía alteración del pH. Predominó la acidemia, con más frecuencia en pacientes sépticos. La causa principal de acidemia parece ser la hipoperfusión. El desenlace es similar en pacientes alcalémicos. Conclusiones: Durante la estancia en la UCI, es frecuente el cambio del pH con igual proporción de acidemia y alcalemia. La mortalidad fue similar en pacientes con ambos trastornos. En pacientes acidémicos, la hipoperfusión parece ser el factor desencadenante más importante.(AU)

Abstract Objective: To determine which changes are seen in serum pH in critical care patients, during their stay in the Intensive Care Unit, stratifying findings according to the main disorder. Design: Quantitative, observational, analytical study of a retrospective cohort. Setting: Polyvalent Intensive Care Unit. Patients, interventions, variables: 753 patients with normal pH after excluding those with insufficient records and history of tubular acidosis. Data was gathered from the clinical database during a 21-month interval. Using a survival analysis, serum pH changes were stratified in their relation to the basic alteration and morbidity. Difference between groups was estimated using the log-rank test. In patients with metabolic acidosis Cox regression was used to search for determining factors. Results: A total of 753 patients were evaluated (median age: 60 years [IQR: 40-71]). The median length of stay was 8 days (IQR: 6-13). pH was abnormal in 42% of the population. Metabolic acidosis was the predominant finding being more frequent in septic patients. The main cause of acidosis seems to be hypoperfusion; outcomes were similar in alkalotic patients. Conclusions: Changes in pH are frequent in patients admitted to intensive care unit, with an equal proportion of acidosis and alkalosis. Mortality was similar in both disorders. pH can be related with a negative outcome in both alkalosis and acidosis. In the latter group hypoperfusion seems to be the major trigger.(AU)

Rheumatoid arthritis accompanied by Gitelman syndrome / 영남의대학술지

Gitelman syndrome is a condition caused by a mutation of the thiazide sensitive Na-Cl cotransporter gene on the distal convoluted tubule. It results in a variety of clinical features, including hypokalemia, hypomagnesemia, hypocalciuria, and metabolic alkalosis. It is often diagnosed in asymptomatic adults presented with unexplained hypokalemia; however, it is sometimes associated with muscular cramps, numbness, fatigue, weakness, or paralysis. We experienced a case of rheumatoid arthritis accompanied by Gitelman syndrome, presented with hand tremor. We diagnosed her using renal clearance study and genetic analysis. Here, we report our experiences regarding this case along with a literature review.

Alteration of Akt, p-Akt, ERK, and p-ERK Proteins Expression in the Kidney of Hypokalemic Rat / 체질인류학회지

Hypokalemia causes metabolic alkalosis and morphological changes of the kidney. K⁺ balance is regulated not only by ion channels or pump gene, but also by various genes including NF-E2-related factor 2 (Nrf2). Previous study suggested the possibility that Akt and ERK kinase may be involved in Nrf2 transcriptional gene activation. In present study, we investigate the alterations of Akt, p-Akt, ERK, p-ERK protein in both normal kidney and K⁺-deficient diet kidney using Western blot analysis, and immunohistochemisrty. Our western blot data showed that the expression of Akt and p-Akt was increased gradually in K⁺-depleted diet (from 1W-3W) compared to normal group. The expression of ERK and p-ERK was markedly increased in K⁺-depleted diet 2W in comparison with normal group. Based on our immunostaining results, Akt protein immunoreactivity was prominently increased in outer medullary collecting duct, especially in K⁺-depleted diet 2 weeks. The localization of p-Akt proteins in K⁺-depleted groups was not different from normal group, but the immunoreactivity was significantly increased in distal convoluted tubule, macula densa and outer medullary thick ascending limb in K⁺-depleted diet 1 and 2 weeks groups. ERK protein immunoreactivity was prominently increased in outer medullary collecting duct, especially in K⁺-depleted diet 2 and 3 weeks. The localization of p-ERK proteins in K⁺-depleted groups was not different from normal group, but the immunoreactivity was prominently increased in the nucleus of outer medullary collecting duct especially in K⁺-depleted diet 2 weeks. Taken together, we suggest that the expression of p-Akt was gradually increased in K⁺-depleted groups of kidney, but the expression of p-ERK was markedly increased in K⁺-depleted diet 2 week group. Hence, the promotion of AKT and ERK phosphorylation in hypokalemic condition may be involved in the regulation of ion channels, ion transporters and subsequent intracellular signal transduction.

Renal intercalated cells and blood pressure regulation

Type B and non-A, non-B intercalated cells are found within the connecting tubule and the cortical collecting duct. Of these cell types, type B intercalated cells are known to mediate Cl⁻ absorption and HCO₃⁻ secretion largely through pendrin-dependent Cl⁻/HCO₃⁻ exchange. This exchange is stimulated by angiotensin II administration and is also stimulated in models of metabolic alkalosis, for instance after aldosterone or NaHCO₃ administration. In some rodent models, pendrin-mediated HCO₃⁻ secretion modulates acid-base balance. However, the role of pendrin in blood pressure regulation is likely of more physiological or clinical significance. Pendrin regulates blood pressure not only by mediating aldosterone-sensitive Cl⁻ absorption, but also by modulating the aldosterone response for epithelial Na⁺ channel (ENaC)-mediated Na⁺ absorption. Pendrin regulates ENaC through changes in open channel of probability, channel surface density, and channels subunit total protein abundance. Thus, aldosterone stimulates ENaC activity through both direct and indirect effects, the latter occurring through its stimulation of pendrin expression and function. Therefore, pendrin contributes to the aldosterone pressor response. Pendrin may also modulate blood pressure in part through its action in the adrenal medulla, where it modulates the release of catecholamines, or through an indirect effect on vascular contractile force. This review describes how aldosterone and angiotensin II-induced signaling regulate pendrin and the contributory role of pendrin in distal nephron function and blood pressure.

Renal intercalated cells and blood pressure regulation

Type B and non-A, non-B intercalated cells are found within the connecting tubule and the cortical collecting duct. Of these cell types, type B intercalated cells are known to mediate Cl⁻ absorption and HCO₃⁻ secretion largely through pendrin-dependent Cl⁻/HCO₃⁻ exchange. This exchange is stimulated by angiotensin II administration and is also stimulated in models of metabolic alkalosis, for instance after aldosterone or NaHCO₃ administration. In some rodent models, pendrin-mediated HCO₃⁻ secretion modulates acid-base balance. However, the role of pendrin in blood pressure regulation is likely of more physiological or clinical significance. Pendrin regulates blood pressure not only by mediating aldosterone-sensitive Cl⁻ absorption, but also by modulating the aldosterone response for epithelial Na⁺ channel (ENaC)-mediated Na⁺ absorption. Pendrin regulates ENaC through changes in open channel of probability, channel surface density, and channels subunit total protein abundance. Thus, aldosterone stimulates ENaC activity through both direct and indirect effects, the latter occurring through its stimulation of pendrin expression and function. Therefore, pendrin contributes to the aldosterone pressor response. Pendrin may also modulate blood pressure in part through its action in the adrenal medulla, where it modulates the release of catecholamines, or through an indirect effect on vascular contractile force. This review describes how aldosterone and angiotensin II-induced signaling regulate pendrin and the contributory role of pendrin in distal nephron function and blood pressure.

HELLP syndrome in a pregnant patient with Gitelman syndrome

Gitelman syndrome is characterized by hypokalemia, metabolic alkalosis, hypocalciuria, and hypomagnesemia. The clinical course of Gitelman syndrome in pregnant women remains unclear, but it is thought to be benign. We report here the first Korean case of atypical eclampsia in a 31-year-old who was diagnosed with Gitelman syndrome incidentally during an antenatal screening test. The patient did well during pregnancy despite significant hypokalemia. At 33 weeks’ gestation, the patient exhibited eclampsia, hemolysis, elevated liver enzymes, low platelets (HELLP) syndrome, and renal insufficiency without significant hypertension or proteinuria. We explain this unusual clinical course through a review of the relevant literature.

Factores asociados a hiponatremia adquirida en la comunidad / Factors associated with community-acquired hyponatremia

El desarrollo de la hiponatremia en la comunidad es un aspecto poco estudiado, y su frecuencia y los factoresque la condicionan son poco conocidos. Objetivos: Estudiar los factores clínicos y de laboratorio asociados a la hiponatremia de pacientes incidentes en el servicio de emergencia de un hospital general. Material y métodos: Estudio de casos y controles. Los casos fueron pacientes con Na+ sérico5 mg/dl. Se contrastaron las variables edad, sexo, sistemas comprometidos, gravedad del paciente y valor de loselectrolitos; gases arteriales; urea y creatinina. El tamaño de muestra fue de 20 casos y 40 controles (confianza 95%, potencia 80% y OR 4)...

The prevalence and associated factors for developing hyponatremia in the community have not been adequately studied. Objectives: To study the clinical and laboratory factors associated with hyponatremia in patients attending the emergency room of a general hospital. Methods: A case-control was carried out, cases were patients with serum sodium values below 135 mEq/l at the time of admission to the emergency room of Hospital Cayetano Heredia and controls were patients admitted at the same time as cases with serum sodium values from 135 y 145 mEq/l. Patients with serum creatinine values >5 mg/dl were excluded...

Pseudohipoaldosteronismo y aparente exceso de mineralocorticoides: cara y ceca en dos pacientes pediátricos / Pseudohypoaldosteronism and apparent mineralocorticoid excess: two faces, two pediatric patients

Los síndromes endocrinológicos con hipofunción o hiperfunción con niveles paradójicos de dosajes hormonales han sido bien caracterizados en los últimos años del siglo XX, a partir del desarrollo de técnicas genéticas y moleculares. Presentamos dos pacientes con pseudohipoaldosteronismo y aparente exceso de mineralocorticoides como síndromes en espejo, con la intención de alertar al médico clínico respecto de su consideración como entidad diagnóstica en niños con alteraciones hidroelectrolíticas. (AU)

Endocrinological syndromes with underactive or overactive hormonal levels with paradoxical dosages have been well characterized over the years of the twentieth century, from the development of genetic and molecular techniques. We present two patients with pseudohypoaldosteronism and apparent mineralocorticoid excess as mirror syndromes, with the aim to alert the clinician regarding their consideration as a diagnostic entity in children with fluid and electrolyte disturbances. (AU)

Extreme Metabolic Alkalosis Caused by Gastrostomy Tube Malposition Treated Using Conventional Hemodialysis / 전남의대학술지

No abstract available.

Milk-alkali syndrome secondary to the intake of calcium supplements / 영남의대학술지

Milk-alkali syndrome (MAS), a triad of hypercalcemia, metabolic alkalosis, and renal failure, is associated with ingestion of large amounts of calcium and absorbable alkali. MAS is the third most common cause of hypercalcemia in hospital, after primary hyperparathyroidism and malignant neoplasm. MAS is not often reported in the Korean literature. We describe MAS secondary to intake of calcium citrate for the treatment of osteoporosis with thoracic spine compression fracture. A 70-year-old man presented to our hospital with a 1-week history of general weakness and lethargy. He was found with acute kidney injury (serum creatinine, 4.6 mg/dL), hypercalcemia (total calcium, 14.8 mg/dL), and alkalosis. Laboratory evaluation excluded both hyperparathyroidism and malignancy. Mental status and serum calcium level was normalized within a week after proper hydration and intravenous administration of furosemide. However, he developed aspiration pneumonia, pseudomembranous colitis, and sepsis with multi-organ failure. Despite intensive treatment including inotropics, mechanical ventilation, and renal replacement therapy, he expired with no signs of renal recovery on the 28th hospital day.