Modulation of ion uptake across posterior gills of the crab Chasmagnathus granulatus by dopamine and cAMP

Comp Biochem Physiol A Mol Integr Physiol. 2004 Sep;139(1):103-9. doi: 10.1016/j.cbpb.2004.07.001.


Cyclic AMP (cAMP) and dopamine modulate ion uptake across isolated and perfused posterior gills of Chasmagnathus granulatus acclimated to 10 per thousand salinity. Addition of cAMP agonists, such as cp-cAMP, forskolin, and IBMX, produced a significant increase in the transepithelial potential difference (Vte), which reflects ion transport activity. Dopamine (DA) also had a stimulatory effect on ion uptake, increasing Vte and Na(+) influx, although this effect was transient, since both variables remained elevated for less than 30 min. In addition, the dose-response curve for DA concentration-Vte was biphasic, and the maximum stimulation was obtained with 10 micromol l(-1). When the effects of forskolin and DA on the Na(+)/K(+)-ATPase activity were tested, they correlated well with the Vte and Na(+) influx experiments; the enzyme activity increased significantly after preincubation of gill fragments for 10 min with forskolin or DA (51 and 64%, respectively), but there was no effect after pre-incubation with DA for 20 min. Finally, KT5720, a specific inhibitor of cAMP-dependent protein kinase (PKA), completely abolished the stimulatory effect of DA on Vte, suggesting the involvement of PKA in this mechanism.

MeSH terms

  • Animals
  • Biological Transport
  • Brachyura / anatomy & histology*
  • Brachyura / physiology*
  • Carbazoles / pharmacology
  • Cyclic AMP / metabolism*
  • Cyclic AMP-Dependent Protein Kinases / antagonists & inhibitors
  • Dopamine / metabolism*
  • Epithelium / metabolism
  • Gills
  • Indoles / pharmacology
  • Ions*
  • Male
  • Membrane Potentials
  • Pyrroles / pharmacology
  • Sodium-Potassium-Exchanging ATPase / metabolism
  • Time Factors


  • Carbazoles
  • Indoles
  • Ions
  • Pyrroles
  • KT 5720
  • Cyclic AMP
  • Cyclic AMP-Dependent Protein Kinases
  • Sodium-Potassium-Exchanging ATPase
  • Dopamine