| First Author | Mironova E | Year | 2017 |
| Journal | Am J Physiol Renal Physiol | Volume | 312 |
| Issue | 6 | Pages | F1073-F1080 |
| PubMed ID | 28179253 | Mgi Jnum | J:272307 |
| Mgi Id | MGI:6282554 | Doi | 10.1152/ajprenal.00401.2016 |
| Citation | Mironova E, et al. (2017) ENaC activity in the cortical collecting duct of HKalpha1 H(+),K(+)-ATPase knockout mice is uncoupled from Na(+) intake. Am J Physiol Renal Physiol 312(6):F1073-F1080 |
| abstractText | Modulation of the epithelial Na(+) channel (ENaC) activity in the collecting duct (CD) is an important mechanism for normal Na(+) homeostasis. ENaC activity is inversely related to dietary Na(+) intake, in part due to inhibitory paracrine purinergic regulation. Evidence suggests that H(+),K(+)-ATPase activity in the CD also influences Na(+) excretion. We hypothesized that renal H(+),K(+)-ATPases affect Na(+) reabsorption by the CD by modulating ENaC activity. ENaC activity in HKalpha1 H(+),K(+)-ATPase knockout (HKalpha1(-/-)) mice was uncoupled from Na(+) intake. ENaC activity on a high-Na(+) diet was greater in the HKalpha1(-/-) mice than in WT mice. Moreover, dietary Na(+) content did not modulate ENaC activity in the HKalpha1(-/-) mice as it did in WT mice. Purinergic regulation of ENaC was abnormal in HKalpha1(-/-) mice. In contrast to WT mice, where urinary [ATP] was proportional to dietary Na(+) intake, urinary [ATP] did not increase in response to a high-Na(+) diet in the HKalpha1(-/-) mice and was significantly lower than in the WT mice. HKalpha1(-/-) mice fed a high-Na(+) diet had greater Na(+) retention than WT mice and had an impaired dipsogenic response. These results suggest an important role for the HKalpha1 subunit in the regulation of purinergic signaling in the CD. They are also consistent with HKalpha1-containing H(+),K(+)-ATPases as important components for the proper regulation of Na(+) balance and the dipsogenic response to a high-salt diet. Such observations suggest a previously unrecognized element in Na(+) regulation in the CD. |
