In mouse mammary epithelial C127 cells expressing wild-type cystic fibrosis transmembrane conductance regulator (CFTR), chloride efflux, measured with the Cl-sensitive dye 6-methoxy-N-(3-sulfopropyl)quinolinium (SPQ), was stimulated by activation of protein kinase A with cyclic AMP elevating agents forskolin plus 3-isobutyl-1-methyl-xanthine (IBMX) and, to a less extent, by activation of protein kinase C with the phorbol 12-myristate 13-acetate (PMA). Conversely, bicarbonate influx, determined by intracellular alkalinization of cells incubated with the pH-sensitive dye 2′,7′-bis(2-carboxyethyl)-5(6)-carboxyfluoresceintetraacetoxym ethyl ester (BCECF-AM), was stimulated by cyclic AMP elevation, but not by PMA. Patch clamp analysis revealed that PMA activated a Cl-current with the typical biophysical characteristics of swelling-activated current and not of CFTR. © 2001 Elsevier Science B.V.
Zegarra-Moran, O., Porcelli, A. M., & Rugolo, M. (2001). The phorbol ester PMA and cyclic AMP activate different Cl- and HCO3/- fluxes in C127 cells expressing CFTR. Biochimica et Biophysica Acta - Molecular Basis of Disease, 1535(2), 120–127. https://doi.org/10.1016/S0925-4439(00)00089-2