PKC activators stimulate H+ conductance in chicken enterocytes

Chicken enterocytes present a H⁺-conducting pathway involved in the recovery of intracellular pH (pH_i) from an acid load. In the current study we have tested the effect of protein kinase C (PKC) activators on the rate of proton efflux through the H⁺-conducting pathway. The rate of proton efflux was increased by the addition of 1,2-dioctanoyl-rac-glycerol (DOG) or phorbol 12-myristate 13-acetate (PMA), but it was not affected by the addition of the inactive phorbol ester analogue, 4-phorbol 12, 13-didecanoate. DOG stimulated the process in a dose-dependent manner with a half-maximal effect at 45 M. Staurosporine and Zn²⁺ prevented the DOG-dependent increase in the rate of proton efflux. The rate of proton efflux was affected by the pH_i and DOG shifted this relationship upward and to the right. These results suggest that the proton-conducting pathway is regulated by PKC.