| First Author | Warth R | Year | 2004 |
| Journal | Proc Natl Acad Sci U S A | Volume | 101 |
| Issue | 21 | Pages | 8215-20 |
| PubMed ID | 15141089 | Mgi Jnum | J:90686 |
| Mgi Id | MGI:3044465 | Doi | 10.1073/pnas.0400081101 |
| Citation | Warth R, et al. (2004) Proximal renal tubular acidosis in TASK2 K+ channel-deficient mice reveals a mechanism for stabilizing bicarbonate transport. Proc Natl Acad Sci U S A 101(21):8215-20 |
| abstractText | The acid- and volume-sensitive TASK2 K+ channel is strongly expressed in renal proximal tubules and papillary collecting ducts. This study was aimed at investigating the role of TASK2 in renal bicarbonate reabsorption by using the task2 -/- mouse as a model. After backcross to C57BL6, task2 -/- mice showed an increased perinatal mortality and, in adulthood, a reduced body weight and arterial blood pressure. Patch-clamp experiments on proximal tubular cells indicated that TASK2 was activated during HCO3- transport. In control inulin clearance measurements, task2 -/- mice showed normal NaCl and water excretion. During i.v. NaHCO3 perfusion, however, renal Na+ and water reabsorption capacity was reduced in -/- animals. In conscious task2 -/- mice, blood pH, HCO3- concentration, and systemic base excess were reduced but urinary pH and HCO3- were increased. These data suggest that task2 -/- mice exhibit metabolic acidosis caused by renal loss of HCO3-. Both in vitro and in vivo results demonstrate the specific coupling of TASK2 activity to HCO3- transport through external alkalinization. The consequences of the task2 gene inactivation in mice are reminiscent of the clinical manifestations seen in human proximal renal tubular acidosis syndrome. |
