| First Author | Pochynyuk O | Year | 2010 |
| Journal | FASEB J | Volume | 24 |
| Issue | 6 | Pages | 2056-65 |
| PubMed ID | 20097874 | Mgi Jnum | J:162364 |
| Mgi Id | MGI:4818752 | Doi | 10.1096/fj.09-151506 |
| Citation | Pochynyuk O, et al. (2010) Dietary Na+ inhibits the open probability of the epithelial sodium channel in the kidney by enhancing apical P2Y2-receptor tone. FASEB J 24(6):2056-65 |
| abstractText | Apical release of ATP and UTP can activate P2Y(2) receptors in the aldosterone-sensitive distal nephron (ASDN) and inhibit the open probability (P(o)) of the epithelial sodium channel (ENaC). Little is known, however, about the regulation and physiological relevance of this system. Patch-clamp studies in freshly isolated ASDN provide evidence that increased dietary Na(+) intake in wild-type mice lowers ENaC P(o), consistent with a contribution to Na(+) homeostasis, and is associated with increased urinary concentrations of UTP and the ATP hydrolytic product, ADP. Genetic deletion of P2Y(2) receptors in mice (P2Y(2)(-/-); littermates to wild-type mice) or inhibition of apical P2Y-receptor activation in wild-type mice prevents dietary Na(+)-induced lowering of ENaC P(o). Although they lack suppression of ENaC P(o) by dietary NaCl, P2Y(2)(-/-) mice do not exhibit NaCl-sensitive blood pressure, perhaps as a consequence of compensatory down-regulation of aldosterone levels. Consistent with this hypothesis, clamping mineralocorticoid activity at high levels unmasks greater ENaC activity and NaCl sensitivity of blood pressure in P2Y(2)(-/-) mice. The studies indicate a key role of the apical ATP/UTP-P2Y(2)-receptor system in the inhibition of ENaC P(o) in the ASDN in response to an increase in Na(+) intake, thereby contributing to NaCl homeostasis and blood pressure regulation. |
