Neuropeptide Y (NPY) and vasoactive intestinal polypeptide (VIP) immunoreactive nerves were demonstrated in 21-day-old embryonic pancreatic tissue fragments transplanted into the anterior eye chamber of rats for 22, 45 and 109 days and in 60-day-old normal adult pancreas using immunohistochemical technique. In normal adult tissue, NPY-positive neurons lie close to the basal and lateral walls of the acinar cells. NPY-containing nerve fiber plexuses were found around blood vessels. VIP-immunopositive nerves were also discernible in the outer parts of the islets of Langerhans and on pancreatic ducts. In the transplants, it is not only the neural elements that survived but also the pancreatic ducts and the endocrine cells. VIP- and NPY-positive neurons were found in the stroma of the surviving pancreatic tissue. The distribution of these neural elements is similar to that of normal tissue in the surviving pancreatic ducts but different with regards to the acinar tissue. This study confirms that intrinsic nerves can survive and synthesize polypeptides even after 109 days of transplantation into the anterior eye chamber.

Animals↗

PubMedDate not supplied

Dopamine-beta-hydroxylase-positive nerves in normal and transplanted pancreatic tissue in the anterior eye-chamber of rats.

Dopamine-beta-hydroxylase(DBH)-positive nerves were demonstrated in normal and in pancreatic tissue fragments transplanted for 22 and 32 days into the anterior eye-chamber of rats using immunohistochemical techniques. Dopamine-beta-hydroxylase-immunopositive neurons of different shapes could be observed in normal pancreas. The neurons had either spindle or oval shapes. In the transplanted tissue, DBH-positive neuronal profiles were found in the stroma. In some cases DBH-immunopositive cells appeared as a cluster of cells around pancreatic ducts and blood vessels or as solitary cells. The wall of pancreatic ducts in the transplants also contained DBH-immunopositive nerve profiles.

Animals↗

PubMedDate not supplied

Ultrastructural cytochemistry of acetylcholinesterase enzyme activity in pancreatic tissue transplants in rats.

The distribution of acetylcholinesterase (AChE) at the ultrastructural level was investigated in normal and in pancreatic fragments transplanted for 56 days into the anterior eye chamber of heterologous rats using enzyme cytochemical methods. Acetylcholinesterase reaction products were seen on the basal surface of the acinar cells in normal pancreas. Acetylcholinesterase enzyme activity was also detected on the axolemma of the surviving nerve fibres. This enzyme reaction product forms alternating thick and thin bands on the axolemma. Some of these AChE-positive nerve fibres accompany blood vessels that also survive after transplantation. AChE were seen in cytoplasm adjacent to the surviving alpha and pancreatic polypeptide cells. We conclude that the ability of some neurons and cells to produce and or store acetylcholinesterase is still retained after transplantation of pancreatic tissue into the anterior eye chamber of rats.

Acetylcholinesterase↗