Action of Acetylcholine on the Epinephrine Output and Blood Sugar of Dogs, and the Splanchnic Nerves

Abstract

Acetylcholine was subcutaneously applied to dogs, normal or doubly splanch-nicotomized, and the output rate of epinephrine and the blood sugar was measured from time to time.
The operation field was previously desensitized by sectioning the corresponding dorsal spinal roots, and the blood from the suprarenal gland was collected through the lumbar approach without fastening the animals or narcotizing. Epinephrine was measured by means of the rab-bit intestine segment method and sometimes also simultane-ously by means of the para-doxical cat pupil reaction.
In normal dogs, 15 mgrms. acetylcholine per kilo of body weight invariably caused an increase of the epinephrine output rate and of the blood sugar concentration, but the excess was at most 0.0001 mgrm. per kilo per minute (from one gland), and 0.01-0.03 per cent sugar respectively.
When applied to the doub-ly splanchnicotomized dogs, the increase was unmistakably large, such as 0.0002-0.0007 mgrm. epinephrine per kilo per minute and 0.02-0.08% respec-tively. And the rapidity with which the hyperepinephrinae-mia and hyperglycaemia developed and disappeared was plainly quick-er in the doubly splanchnicotomized ones. In order to explain this strange fact, it may be tentatively, suggested that an inhibitory im-pulse is running through the splanchnic nerves in the acetylcholine poisoning, while the drug acts directly on the suprarenal medulla to liberate epinephrine.