Stimulation of NaCl secretion in the rectal gland of the dogfish Squalus acanthias

1. The rectal gland of the dogfish (Squalus acanthias) secretes NaCl when stimulated by a hormone related to vasointestinal peptide. 2. Patch clamp and microelectrode techniques are used to examine the changes in membrane conductances occurring with hormonal stimulation. 3. The conductance of the “resting” cell is dominated by basolateral K+ channels. 4. Hormonal stimulation “opens” apical Cl− channels. 5. This opening of apical chloride channels appears to be mediated by cAMP-dependent phosphorylation of pre-existing closed channels