Biochemical characteristics and protein composition of murine saliva evoked in vivo by receptor-selective agonists.

We have demonstrated that the proteins of mouse saliva secreted in vivo are dependent on the nature of the stimulus, both qualitatively and quantitatively. The electrophoretic pattern of salivary proteins obtained by stimulation with phenylephrine is different from that evoked by carbamylcholine or isoproterenol. The electrophoretic pattern of alpha-adrenergic saliva largely resembles that of the proteins secreted in vitro by male submandibular glands, indicating that these proteins are predominantly derived from the granular convoluted tubular cells of submandibular glands. Secretion of proteins from acinar cells of parotid and submandibular glands was particularly stimulated by beta-adrenergic agonists and, to a lesser extent, by cholinergic agonists. The data from the in vivo induced salivas are in agreement with the morphological data on the regulation of the secretory process from parotid and submandibular glands. On the other hand, the secretory process in vitro does not occur specifically, whereas that in vivo does.