Effect of subcutaneous pancreatic tissue transplants on streptozotocin-induced diabetes in rats. III. Distribution of neuropeptides in normal and diabetic (host) pancreas

This study examines whether there is a change in the pattern of distributio n of cholecystokinin-octapeptide (CCK-8), calcitonin-gene-related peptide ( CGRP), neuropeptide-Y( (NPY), substance P (SP) and vasoactive intestinal po lypeptide (VIP) in the pancreas of streptozotocin (STZ)-diabetic (host) rat s after subcutaneous pancreatic transplantation. Varicose CCK-8-immunoposit ive nerve fibres were observed in the wall of blood vessels of both normal and diabetic host pancreata, The density of CCK-8-immunoreactive varicose n erve fibres appeared to have increased in host rat pancreas. CGRP was demon strated in many nerve fibres located in the wall of blood vessels of both n ormal and host pancreas. CGRP, however, seemed to be better expressed in th e nerves of host pancreas when compared to normal. The pancreata of both no rmal and diabetic (host) rats contained numerous NPY-immunopositive varicos e nerve fibres located in the wall of blood vessels. SP was demonstrated in neurons located in the interlobular areas of normal tissue and in fine var icose nerve fibres of the interacinar region of the pancreas of STZ-induced diabetic rats with SPTG. In normal pancreatic tissue, VIP-immunopositive n erve fibres were observed in all areas of the pancreas. VIP-positive nerve fibres were still discernible especially in the interacinar regions of the pancreas of host rats. In conclusion, the pattern of distribution and densi ty of NPY, SP and VIP in the pancreas of STZ-induced diabetic rats with SPT G is similar to that observed in normal pancreas, but the expression of CGR P and CCK-8 seemed to have increased as a result of transplantation and or diabetes.