Abstract
Salivary secretion from the ducts of the submaxillary and sublingual glands of dogs has been estimated without narcotizing the animal. Estimation was done without as well as with showing or giving food; no precaution was taken for avoiding establishing the condition reflex.
The chorda tympani and the lingual nerve were cut out in a length of about 1 centimetre and 2-3-4 cms. respectively. The upper cervical ganglion was excised. In some cases the submaxillary gland was decapsulated, only the large vessels being left behind. Their wall was however mechanically cleaned. In a few cases the sublingual gland was excised; in some cases its anterior portion was removed. And further the splanchnic nerves were bilaterally sectioned, the liver and the thyroid glands were also denervated. In a few cases the glossopharyngeal nerve was interfered with by pulling out the nodular ganglion from the foramen lacerum.
In face of denervating the submaxillary gland in the manner above described, the gland continued to secrete though quiet small, and really on response to feeding. We never came to see a continuous salivary secretion without co-existence of that on feeding. There were always reflex secretion and psychical secretion. Thus we must seriously doubt the validity of the experimental results reported by previous workers, on which the view of the paralytic secretion originated. Since we are unable to abolish totally salivary secretion causable by giving and showing food, we are not in the position to decide whether or not the salivary gland can secrete saliva notwithstanding abolishing of the secretion on feeding.
The remaining secretion of saliva causable by feeding and psychically seems of a reflex nature from its short latency, but the present writer has failed to find the path way. The salivary glands besides that under question were removed too, but no effect was noted at all.
The remaining secretion of saliva was of quite small quantity on the day or the day next to the denervation, which was done under local and general anaesthesia respectively, but a few days later it became a little larger. Afterwards it fluctuates somewhat and showed a tendency to increase but very slowly. But about two months after the denervation the increase became pretty abrupt.
Removal of the upper cervical ganglion, denervation of the liver and of the thyroid glands did not alter the salivary secretion of the gland, deprived of the parasympathetic innervation. The splanchnicotomy left behind an evident augmentation in the salivary secretion from the denervated gland in a single instance surely, but in the others no effect was detectable.
Fastening of the animal on the table, asphyxiation, or applying tobacco smoke or ammonia into the nose was capable of augmenting the salivary secretion from the denervated gland, but rather insignificant and not constant. It is hopeless to use salivary secretion from the denervated gland as the indicator in the quantitative estimation of epinephrine secretion even if it may be permitted to take it as such. Ether evoked abundant outflow of saliva from the denervated gland, even after the double splanchnicotomy.
