title: Neuropeptides of human thymus in normal and pathological conditions.
abstract: Human thymus of healthy subjects and patients affected by thymoma-associated Myastenia Gravis were studied in order to visualize and compare the morphological distributive pattern of four neuropeptides: vasoactive intestinal peptide, substance P, neuropeptide Y, and neurotensin. Based on our observations, we formulated hypotheses on their relations in neuro-immunomodulation under physiological and pathophysiological conditions. Immuno-histochemical staining for neuropeptides was performed and morphological and morphometrical analyses were conducted on healthy and diseased thymus. In normal thymus, a specific distributive pattern was observed for the several neuropeptide-positive nerves in different thymus lobular zones. In particular substance P-positive fibers were observed in subcapsular zone, specifically located into parenchyma, where they represent the almost total amount of fibers; neurotensin-positive fibers were observed primarily located in parenchyma than perivascular site of several thymus lobular zones, and more abundant the cortico-medullary and medullary zones. Instead VIP- and NPY-positive fibers were widely distributed in perivascular and parenchymal sites of several thymus lobular zones. In thymoma, the distribution of neuropeptide-positive fibers was quantitatively reduced, while cells immunopositive to VIP and substance P were quantitatively increased and dispersed. Observation of the perivascular and parenchymal distribution of the analyzed neuropeptides suggests evidence that a regulatory function is performed by nerves and cells that secrete neuropeptide into the thymus. The alteration of neuropeptide patterns in thymoma suggests that these neurotransmitters play a role in autoimmune diseases such as Myastenia Gravis.
authors.affiliation: Anatomia Umana, Scuola di Scienze del Farmaco e dei Prodotti della Salute, Università di Camerino, Italy. fiorenzo.mignini@unicam.it
authors.forename: F
authors.initials: F
authors.lastname: Mignini
authors.forename: M
authors.initials: M
authors.lastname: Sabbatini
authors.forename: V
authors.initials: V
authors.lastname: D'Andrea
authors.forename: C
authors.initials: C
authors.lastname: Cavallotti
mesh_terms: D000328:Adult; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D009157:Myasthenia Gravis / Q000378:metabolism / Q000473:pathology; D009478:Neuropeptide Y / Q000378:metabolism; D009479:Neuropeptides / Q000378:metabolism*; D009496:Neurotensin / Q000378:metabolism; D013373:Substance P / Q000378:metabolism; D013945:Thymoma / Q000378:metabolism / Q000473:pathology; D013950:Thymus Gland / Q000378:metabolism* / Q000473:pathology*; D014660:Vasoactive Intestinal Peptide / Q000378:metabolism
chemical_list: D009478:Neuropeptide Y; D009479:Neuropeptides; D013373:Substance P; D014660:Vasoactive Intestinal Peptide; D009496:Neurotensin