The whole homogenate was obtained from mouse pituitary glands and kidneys and used for immunoblotting analyses as previously described.(9 (link),25 (link)) Protein samples were added to the sample buffer in the presence of 2-mercaptoethanol and subjected to sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). The separated proteins were transferred by electrophoresis to Immobilon-P polyvinylidene difluoride (Millipore, Billerica, MA) and treated with diluted antibodies. Signals were detected using Immobilon Western (Millipore).