Immunohistochemical study of intrinsic innervation in the human pancreas.

: Immunohistochemical identification of nerve structures in the human pancreas was achieved using immunohistochemical techniques. The antibodies used are specific for the myelin present in the periphery of ganglia and pregangliar nerve fibers, and for adrenergic neurotransmitters as well. In this study we observed the presence of numerous ganglia and nerve fibers in the periacinar tissue and near vascular structures. Adrenergic neurotransmitters were detected within pancreatic islets. These results would reveal that the exocrine pancreatic component is mainly innervated by parasympathetic ganglia and pregangliar fibers, as observed in the alimentary canal. Diversely, the endocrine component seems to be regulated by nonmyelinic orthosympathetic postgangliar fibers and parasympathetic fibers forming the perivascular plexus. The morphology and distribution of nerve structures in the pancreas recall those of the alimentary canal because these organs share the same embryogenetic derivation.