MASTICATORY-SALIVARY REFLEXES MOBILIZE NONADRENERGIC, NONCHOLINERGIC SECRETORY MECHANISMS IN PAROTID-GLANDS OF CONSCIOUS RATS

All rats were maintained on liquid diet, prepared from their ordinary hard pelleted diet, for a week, then fasted 32-33 h and subsequently either fed liquid or pelleted diet for 60-90 min or serving as non-fed controls. Both the fed and the non-fed animals had received atropine and alpha- and beta-adrenoceptor antagonists 15 min before the test. The rats given the liquefied chow consumed about twice as much as those given the hard chow, In the parotid glands of the rats given hard chow the number of acinar granules and the total amylase activity were reduced, by 50 and 70%, respectively, as compared with the glands of control rats. In the parotid glands of the rats given liquefied chow the number of acinar granules and the total activity of amylase remained unchanged. The results suggest that non-adrenergic, non-cholinergic secretory mechanisms of the rat parotid gland participate in masticatory-salivary reflexes.