Immunohistological demonstration of insulin and glucagon in islet tissue of reptiles, amphibians and teleosts using epoxy-embedded material and antiporcine hormone sera.

Islet tissue from 2 reptilian, 5 amphibian and 7 teleost species was fixed in glutaraldehyde, embedded in epoxy-resin, stored for up to 3 years, cut in ultrathin sections and stained with the indirect immunofluorescent technique for insulin and glucagon following removal of the plastic. The antisera were directed against porcine insulin and glucagon, or FITC labeled and directed against the globulin fraction of the producer species. Positive results were obtained in species from all vertebrate classes investigated. Insulin demonstration in teleosts was particularly difficult.