Fig. 5. The influence, in stingrays acclimated to ion-poor Rio Negro water, of (A) amiloride (10^-4 mol l^-1) and (B) DIDS (2x10^-5 mol l^-1) on unidirectional (J_in, J_out) and net flux rates of Na⁺ (open bars) and Cl^- (hatched bars) during three successive 2 h periods. Values are means ± 1 S.E.M. (N=5). Other details as in the legend of Fig. 4.