Autonomic control of von Ebner's lingual salivary glands and implications for taste sensation

Abstract

To learn the nature of the autonomic control of the serous lingual salivary glands of von Ebner, parasympathetic and sympathetic agonists were injected into rats, and the extent of depletion of the secretory granules in gland acini was measured. Injection of the [beta]-adrenergic agonist isoproterenol caused a concentration-dependent reduction of the secretory granule content of the acinar cells. Injection of the [beta]-adrenergic antagonist propranolol, combined with isoproterenol, blocked the reduction in secretory granule content seen with isoproterenol alone. Injection of the parasympathetic agonist carbachol also produced a concentration-dependent reduction in granule content of the acini. This reduction was partially blocked by injection of atropine, and completely blocked by injection of atropine and propranolol. [beta]-Adrenergic and parasympathetic agonists alone did not cause total degranulation of the acini. However, this was achieved by injection of both agonists. It is concluded that protein secretion in von Ebner's glands is under both sympathetic and parasympathetic nervous control. It is hypothesized that the glands contain two sets of granules with different compositions, each under the control of either the parasympathetic or sympathetic nervous system. Because von Ebner's glands are closely associated with taste buds and because the glands supply the microenvironment of these taste buds the secretion of these glands may be very important in the mechanism of taste transduction.