A 12-year-old boy presents with progressive muscle weakness and poor growth. Vital signs show BP 118/76 mmHg, HR 94/min, RR 18/min, temperature 37°C, and SpO2 98% on room air. Laboratory studies reveal serum potassium 2.8 mEq/L, pH 7.48, HCO3− 32 mEq/L, and urine chloride 65 mEq/L with elevated urinary calcium excretion. Serum creatinine and BUN are normal. Which renal tubular transporter is most likely defective?
- A)Epithelial sodium channel in collecting duct
- B)Na K 2Cl cotransporter in thick ascending limbGABARITO
- C)Na Cl cotransporter in distal convoluted tubule
- D)Sodium bicarbonate cotransporter in proximal tubule
- E)Aquaporin 2 water channel in collecting duct
Explicação
Na K 2Cl cotransporter in the thick ascending limb is correct. Bartter syndrome mimics chronic loop diuretic use, causing hypokalemic metabolic alkalosis, normal blood pressure, and hypercalciuria. Defective reabsorption in the thick ascending limb increases d... Ver explicação completa e trilha adaptativa →