Non-adrenergic, non-cholinergic parasympathetic secretion in the rat submaxillary and sublingual glands.

Atropine resistant secretion from the submaxillary and sublingual glands was demonstrated upon electrical stimulation of the chorda-lingual nerve at high frequencies. The flow rate of the protein-rich saliva was low, and it declined rapidly and markedly upon prolonged stimulation. The results show that one or more substances other than acetylcholine are released by parasympathetic stimulation and that they may be of importance for the regulation of the exocrine functions of the glands. When the continuous mode of electrical stimulation at a low frequency of the nerve was changed to an intermittent mode of stimulation at a high frequency (in the absence of atropine), the secretion of fluid and protein decreased.