PENTACHLOROPHENOL (PCP) INHIBITS ION-TRANSPORT IN THE ISOLATED TOAD CORNEA

1. Active chloride transport from the stroma to the epithelial surface (tear side) accounts for 80% of the amphibian cornea short-circuit cu rrent (SCC). 2. The effect of pentachlorophenol (PCP, a wood preservat ive) on the bioelectric parameters of the toad Caudiverbera caudiverbe ra isolated cornea was studied. 3. PCP applied to the epithelial surfa ce in the concentration range 0.3-4.3 muM caused a dose-dependent inhi bition of the PD and of the SCC in 7 corneas. This inhibition was irre versible at all concentrations after several washouts. The agent had n o effect when applied to the endothelial surface. 4. In 4 experiments the inhibitory effect was partly reversed by the addition of 1 muM cal cium ionophore A-23187 to the epithelial surface. 5. It is concluded t hat PCP is an inhibitor of corneal active chloride transport and that this structure shows greater sensitivity to this agent than other tiss ues.