Porcine gastric insulin.

We recently found that plasma from pancreatectomized pigs contained concentrations of insulin of 5-10 muU/ml up to five days after pancreatectomy. In search of an extrapancreatic source of insulin, acid-ethanol extracts of porcine stomach and small bowel mucosa were investigated for the presence of insulin. The extracts of the stomach contained large amounts of insulin immunoreactivity while insulin was not detectable in extracts of the small bowel. Upon gel filtration, immunoreactive insulin eluted from the gastric mucosa in a major peak corresponding to the elution volume of an insulin standard and a minor peak corresponding to the elution volume of a proinsulin standard.