[Metasympathetic system and neuroendocrine elements of the human cecal appendix. Immunohistochemical study]

This study was carried out to demonstrate the neuroanatomical bases of pain in non inflamed appendices. Fifty human cecal appendices were examined by means of an immunohistochemical method utilizing antibodies for S100 protein, Neuron Specific Enolase, Chromogranin A and Serotonin. In all samples histological analysis did not demonstrate inflammatory alterations. The neuroendocrine pattern was investigated. Results show numerous nerve fibers and ganglions around the muscle layers and within the submucosa and the lamina propria. Large neuroendocrine cell population shows immunohistochemical staining for chromogranin and serotonin. Neurogenous hyperplasia and the high density of epithelial neuroendocrine cells in non inflamed appendices suggest that neural mechanism and serotonin release from neurosecretory cells are implicated in appendical pain. The nerve hyperplasia might be the effect of serotonin release.