Characterization of cGMP-related phosphodiesterase isoenzymes in rat salivary glands

 Isolation and characterization of the cGMP-related phosphodiesterase (PDE) isoenzymes in rat salivary glands were investigated. Both cGMP- and cAMP-PDE activities were mainly present in the 100 000 g supernatant fractions from the parotid, submandibular, and sublingual glands. The results of inhibition studies and ion-exchange chromatography suggest that Ca2+/calmodulin markedly stimulates PDE1 in the parotid and sublingual glands, and slightly in the submandibular gland. PDE2 was detected only in the parotid gland. PDE3 was identified in the parotid and submandibular glands. PDE5 was detected in the submandibular and sublingual glands by using inhibition studies, ion-exchange chromatography, and Western blotting.