Peptides in metabolic autonomic nerves.

Most polypeptides originally assigned to a specific organ and a specific effect seem to occur in many different parts of the body, in neurons as well as in endocrine cells. Thus gastrin and insulin, or very similar peptides can be demonstrated in extracts of the vagal nerves and of peripheral somatic nerves. Electrical stimulation of the sciatic nerve of a perfused cat leg causes appearance of gastrin and insulin like immunoreactivity in the perfusates. This gastrin and insulin like immunoreactivity might originate from nervous depots. If so it might be assumed that insulin and other peptides are released in response to activation of autonomic or somatic nerves and that they might exert local metabolic effects in response to the acute needs of energy in eg. striated or smooth muscles.