Bicarbonate and the trans-endothelial short circuit current of human cornea.

Experiments were performed in vitro, to determine the effect of bicarbonate ion concentration on human cornea endothelial potential difference, short circuit current and resistance. Decreasing the bicarbonate concentration resulted in a reversible and parallel fall in potential differences and short circuit current, whereas resistance remained unchanged. The results demonstrate that bicarbonate is a necessary component of the mechanisms that generate trans-endothelial short circuit current. Similarities between data derived from rabbit, ox and human suggest that a common underlying bicarbonate dependent mechanism is operating in these species.