Response of a dog kidney cell line (MDCK) to antidiuretic hormone (ADH) with special reference to activation of protein kinase

Antidiuretic hormone (ADH) increased the adenosine 3′,5′-cyclic monophosphate (cAMP) content of cultured cells of the MDCK line, derived from normal dog kidney, after activation of adenylate cyclase. Parathyroid hormone and insulin did not affect the cAMP content of the cells and ADH did not increase the cAMP content of HeLa or 3T6 cells. Thus the effect of ADH on MDCK cells was specific. ADH activated the protein kinase of MDCK cells. Conversion of cAMP-dependent protein kinase to a cAMP-independent catalytic subunit in the ADH-treated cells was demonstrated by glycerol density gradient centrifugation.