Our previous studies have shown that cholecystokinin and pilocarpine are known to be extracellular messengers promoting the release of immunoglobulins A and G antibody activity in the lumen of the rat intestine. In the present study, which was also performed in rats, we show that CCK also promotes the translocation of albumin, electrolytes, and water into the lumen of the intestine. The effect of CCK on the translocation of immunoglobulins, albumin, and electrolytes is reduced by the prior injection of the calcium-channel blocker verapamil and the chloride-channel blocker furosemide. Taken together, the above observations suggest that the translocation of immunoglobulins, albumin, and electrolytes in the intestine appears to be stimulated by identical mechanisms and to proceed simultaneously.