The effects of aluminium and low pH on chloride fluxes in the brown trout, Salmo trutta L

Juvenile S. trutta were exposed to pH 4.0 for 2 h at 10C. The acidity in the medium caused a 66 per cent reduction of the influx rate and a 144 per cent increase in the efflux rate of chloride. Removal of the acid stress returned the influx rate to 89 per cent of the former value at pH 7.0. The effect of aluminium at a final concentration of 6.5 uM depended strongly on the pH of the medium. At pH 7.0, aluminium stimulated chloride efflux by 105 per cent and influx was not affected. At pH 4.0, efflux was not affected but influx reduced to 55 per cent. At pH 5.5, influx was reduced by 62 per cent and efflux was increased by 67.5 per cent.