Prolonged trophic effects of vagal innervation on diaphragm

¹ Department of Gastro-Intestinal Research, Medical Research Institute of Michael Reese Hospital and Medical Center, and Department of Pharmacology, Chicago Medical School, Chicago, Illinois

It has been shown that if the proximal end of a cut vagus nerve is anastomosed to the distal end of a cut phrenic nerve, the musculature of the hemidiaphragm is preserved, although inactive; it contracts upon direct stimulation and, also, upon stimulation of the vagus nerve above its anastomosis. These observations lasted for 22.7–31.5 months and confirm previous work which was of shorter duration. Thus, it is demonstrated that preservation of structure of muscle by innervation by a "foreign" nerve may last, perhaps indefinitely, in the absence of the normal respiratory motion of the hemidiaphragm.

Key Words: vagophrenic anastomosis • muscle innervations and structure • nervous trophic effects • dog diaphragm

Submitted on July 1, 1963