PGF stimulates the 10-pS Cl channel and thiazide-sensitive Na-Cl cotransporter in the distal convoluted tubule.

We used patch-clamp and Western blot analysis to test whether PGF stimulates the basolateral 10-pS Cl channel and thiazide-sensitive Na-Cl cotransporter (NCC) in the distal convoluted tubule (DCT) via a prostaglandin F receptor (FP-R). Single channel and whole cell recordings demonstrated that PGF stimulated the 10-pS Cl channel in the DCT. The stimulatory effect of PGF on the Cl channel was mimicked by a FP-R agonist, latanoprost, but was abrogated by blocking FP-R with AL8810. Also, the effect of PGF on the Cl channel in the DCT was recapitulated by stimulating PKC but was blocked by inhibiting PKC. Furthermore, inhibition of p38 MAPK but not ERK blocked the effect of PGF on the 10-pS Cl channel. Inhibition of NADPH oxidase also abrogated the stimulatory effect of PGF on the 10-pS Cl channel, while the addition of 10 μM HO mimicked the stimulatory effect of PGF on the 10-pS Cl channel. Moreover, superoxide-related species may mediate the stimulatory effect of PGF on the 10-pS Cl channel because the stimulatory effect of PGF and HO was not additive. Western blot analysis showed that infusion of PGF in vivo not only increased the expression of FP-R but also increased the expression of total NCC and phosphorylated NCC. We conclude that PGF stimulates the basolateral 10-pS Cl channel in the DCT by activating FP-R through PKC/p38 MAPK and NADPH oxidase-dependent pathways. The stimulatory effects of PGF on the Cl channel and NCC may contribute to PGF-induced increases in NaCl reabsorption in the DCT.