| Abstract: | Dibutyryl cyclic AMP (50-1000 microM) was found to increase the initial rate of efflux of taurocholic acid from isolated rat hepatocytes. Efflux of the bile acid was inhibited by sodium, and in the absence of sodium dibutyryl cyclic AMP failed to stimulate the rate. Increasing the concentration of calcium from 0 to 1.2 mM had no effect on the initial rate of taurocholic acid efflux from the cells, but the absence of calcium markedly reduced the effect of dibutyryl cyclic AMP. The results suggest that changes in the fluxes of sodium and calcium are involved in the effect of the cyclic nucleotide on taurocholic acid efflux from the cells. |
