Re-innervation of pancreatic tissue implants in normal and in sympathetically denervated eyes of rats.

Embryonic, newborn and adult pancreatic tissue fragments were implanted into the anterior eye-chamber of rats of the same offspring to determine whether there is any difference in the pattern of their re-innervation. In another experiment the embryonic pancreatic tissue fragments were implanted into sympathetically denervated eyes of homologous rats. Newborn, adult and embryonic pancreatic tissue implants were removed under a stereo-microscope after 17, 45 and 53 days, respectively. The embryonic pancreatic tissue implants in denervated eyes were removed after 46 days. The implants were processed for electron microscopy. The embryonic, newborn and adult pancreatic tissue implants were equally well re-innervated by agranular and granular vesicle-containing nerve terminals and varicosities from the host iris. The embryonic pancreatic tissue implants were also re-innervated in sympathetically denervated eyes, most likely by parasympathetic nerves of the iris. Except for the few intrinsic nerve profiles, the re-innervating nerve fibres seemed to reach the implant stroma through the blood vessels revascularizing the implants. The re-innervation of the endocrine pancreas is more pronounced than that of the whole tissue.