Abstract

Significant submandibular salivary gland enlargement occurred in female rats after multiple injections of isoproterenol, incisor teeth amputation or intraorally administered papain. The magnitude of this enlargement was related in each case to the intensity and duration of the stimulus. Reserpine and guanethidine prevented the glandular enlargement induced by papain or amputation. Phenoxybeazamine, an adrenergic alpha receptor antagonist, enhanced glandular growth induced by papain or amputation, whereas the adrenergic beta receptor antagonist, MJ 1999, inhibited glandular growth elicited by isoproterenol, papain or amputation. Propranolol antagonized the effects of isoproterenol and papain but not amputation. Amidephrine, a potent alpha receptor stimulant, did not induce glandular growth, whereas epinephrine, norepinephrine and ethylnorepinephnine did. These effects were blocked by propranolol but not phenoxybenzamine. Aminophylline initiated glandular enlargement, and this effect was slightly augmented by phenoxybenzamine and antagonized by propranolol. The salivary gland growth induced by sympathomimetic amines, amputation or papain seems to involve, predominantly, stimulation of adrenergic beta receptors.