Active absorption of CL- and NA+ in posterior gills of Chinese crab Eriocheir sinensis: Modulation by dopamine and cAMP

Abstract

Isolated posterior gills from the Chinese crab Eriocheir sinensis acclimated to freshwater (FW) were used for perfusion. Dopamine and dibutyryl cAMP (db-cAMP) induced a significant increase of 36Cl- influx. When amiloride, a specific sodium selective channels blocker, was added to the incubation saline, it induced a dramatic decrease of 22Na+ influx, and such an effect could be reversed by dopamine or db- cAMP. In the same experimental condition, we observed that ouabain added to the serosal side induced a marked decrease of the stimulating effect of db-cAMP on 22Na+ uptake across the epithelium to the hemolymph, suggesting that dopamine stimulates Na+ and Cl- influxes via cAMP and Na+/K+-ATPase pathways.