Regulation by sympathetic nervous system of accelerated growth of salivary glands of rats

Abstract

Although the early (24-hr) effect of unilateral extirpation of the superior cervical sympathetic ganglion is to increase the weight of the submandibular salivary gland on the operated side, ganglionectomy subsequently results in an inhibition of the normal growth of the ipsilateral submandibular gland, evident within 8 days. Prior ganglionectomy almost completely prevents the increase in weight of the ipsilateral gland which otherwise follows either amputation of the lower incisor teeth or resection of the inferior alveolar nerve. The increase in gland weight which follows a single amputation of the incisors was significantly inhibited in rats treated with reserpine or bretylium tosylate, drugs which interfere with the storage or release of norepinephrine by sympathetic nerves. It is concluded that these data support the hypothesis previously offered that the sympathetic nervous system may be involved both in the accelerated growth of the submandibular glands that follows amputation of the lower incisor teeth and in the maintenance of normal salivary gland size.