Effects of saline exposure on the response of toad bladder (Bufo marinus) to aldosterone.

1. The short-circuit current response of toad bladders to high concentrations of aldosterone (2 x 10(-7) M) has been investigated following saline exposure of toads. 2. Limited saline exposure appears to enhance the aldosterone-stimulated response. 3. Additional saline exposure results in a reduced aldosterone response. 4. Overnight pre-incubation of isolated bladders proved a better pretreatment condition for study of an aldosterone short-circuit current response. 5. Plasma aldosterone concentrations and studies of [3H]aldosterone binding in the bladders have failed to demonstrate significant effects of saline exposure on endogenous aldosterone concentrations.