Effects of neonatal sympathetic denervation on amylase secretion in the adult rat parotid gland: difference in beta 1- and beta 2-adrenoceptor response.

Changes in amylase secretion and cyclic AMP accumulation in response to various secretagogues were studied in parotid glands of adult rats subjected to neonatal sympathetic denervation by unilateral excision of the superior cervical ganglion. Denervation decreased the gland content of amylase and both basal and the stimulated levels of cyclic AMP were elevated. The secretory cells of neonatally denervated glands exhibited enhanced maximal enzyme discharge in response to beta-adrenoceptor agonists. However, the selective beta 1-agonist, prenalterol was not effective in this respect whereas an enhanced maximal secretory response to the beta 2-selective agonist, terbutaline, was particularly prominent. DBcAMP was also more efficient in inducing amylase release from the denervated gland. The result of the present study demonstrate that the usual dominance of the beta 1-adrenoceptor subtype in eliciting amylase release is lost, implying that the differentiation of the beta-adrenoceptor into its subtypes is altered by neonatal sympathetic denervation.