Insulin or insulin-like peptides in the human pituitary

Human pituitary cells and pancreatic islet beta cells from surgical and autopsy material showed positive immunoreactivity to anti-porcine insulin antisera demonstrating the presence in these tissues of insulin or insulin-like immunoreactive material. Glutaraldehyde-fixed, one micron epoxy sections were used and the polymerized resin was removed prior to staining with the peroxidase anti-peroxidase technique using guinea pig antisera to porcine insulin. Pancreatic beta cells served as the positive control, and appropriate negative controls were also utilized.