EFFECT OF AMYTAL ON THE AUTONOMIC NERVOUS SYSTEM AS INDICATED BY THE SALIVARY GLANDS

¹ Department of Physiology, McGill University, Montreal

1. Amytal in amounts sufficient for anesthesia (0.5 cc. per kilogram body weight) greatly affects the parasympathetic innervation of the submaxillary salivary gland in the dog. The secretory effect from chorda tympani stimulation and also the action of choline and acetyl-choline are diminished, and under large doses of up to 2 cc. per kilogram body weight are completely abolished.

2. The sympathetic secretory innervation of the submaxillary gland is also disturbed but in a less marked degree than the parasympathetic.

3. After almost complete paralysis of the chorda tympani by amytal and failure of the usual secretory effect of acetyl-choline, the gland responds with a prompt and copious secretion of saliva to average doses of pilocarpine, introduced intravenously.

4. Subminimal doses of physostigmine to a certain extent restore the action of the parasympathetic secretory nerve when paralyzed by amytal; it also temporarily increases the heart rate and raises the blood pressure, improving the condition of the animal though only transiently.

5. The vaso-dilatation which occurs during chorda tympani stimulation is diminished but not completely abolished by amytal, whereas the vaso-constrictor effect of sympathetic stimulation is greatly diminished and sometimes completely absent at the end of the experiment.

6. Under the excessive doses of amytal used throughout this investigation, the death of the animal took place after several hours from circulatory shock with a gradual fall of the blood pressure and diminishing activity of the heart.