8-P-CHLOROPHENYLTHIO-CYCLIC AMP - POTENT PARTIAL SIMULATOR OF ANTI-DIURETIC HORMONE ACTION

Abstract

In the toad urinary bladder 8-p-chlorophenylthio-cyclic[c]AMP mimics the stimulatory effects of antidiuretic hormone on osmotic H2O permeability, 3H2O diffusion and transepithelial Na transport, but unlike the hormone it does not cause an increase in urea permeability. Threshold activation for the hydroosmotic response is observed at 1 .mu.M and full activation at 100 .mu.M. These results suggest that cAMP may not mediate all the physiological effects of antidiuretic hormone and that this highly potent cAMP analog may be useful in elucidating the precise role of cAMP in other biological systems where this nucleotide is thought to mediate hormone action.