Specific 3H-cimetidine binding to receptors in the submandibular gland of the rat.

Recent studies indicate that the secretagogue action of histamine on the salivary gland is mediated via H2-receptors. In this study we attempt to characterize the histamine H2-receptors in the submandibular gland of the rat. The results show the presence of a specific 3H-cimetidine binding site in the gland. However, the binding constants of this site are not fully characteristic of the specific 3H-cimetidine-H2-receptor binding. They tend to indicate that the binding of 3H-cimetidine to the gland membrane is similar to the well-characterized 3H-cimetidine-imidazole-recognition-receptor binding found in the membrane of the brain, gastric mucosae and atrium of various mammalian species.