Following treatment with cholinergic and beta-adrenergic drugs, the beta-type protein, associated with cAMP, was secreted regardless of the doses used. 2. Following treatment with alpha 1-adrenergic drugs, both the beta-type and alpha-type proteins were secreted depending on the doses used and the alpha-type protein was completely converted to the beta-type with alpha-blockers. 3. Following treatment with alpha 2-adrenergic drugs, the gamma-type protein, associated with cGMP, was secreted independent of the doses used.