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Peptidergic and Nitrergic Innervation of the Pineal Gland in the Domestic Pig: An Immunohistochemical Study
Author(s) -
Nowicki M.,
Wojtkiewicz J.,
Lewczuk B.,
Kosacka J.,
Majewski M.,
PrzybylskaGornowicz Barbara
Publication year - 2007
Publication title -
anatomia, histologia, embryologia
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.34
H-Index - 35
eISSN - 1439-0264
pISSN - 0340-2096
DOI - 10.1111/j.1439-0264.2007.00767.x
Subject(s) - vasoactive intestinal peptide , pinealocyte , endocrinology , medicine , calcitonin gene related peptide , pineal gland , calcitonin , biology , neuropeptide , chemistry , receptor , melatonin
Summary The presence and co‐localization of vasoactive intestinal polypeptide (VIP), peptide N‐terminal histidine C‐terminal isoleucine (PHI), pituitary adenylate cyclase‐activating peptide (PACAP), somatostatin (SOM), calcitonin gene‐related peptide (CGRP), substance P (SP) and the neuronal isoform of nitric oxide synthase (NOS) were studied in neuronal structures of the pig pineal gland. Paraformaldehyde‐fixed pineals of 3‐month‐old gilts were sliced into serial cryostat sections, which were subjected to a set of double immunofluorescence stainings. Based on the co‐existence patterns of neuropeptides, five populations of nerve fibres supplying the pig pineal were distinguished: (1) PHI‐positive, (2) PACAP‐positive, (3) SOM‐positive, (4) SP/CGRP‐positive and (5) SP‐positive/CGRP‐negative. Only a subpopulation of PHI‐positive fibres contained VIP at the level detectable by immunofluorescence. NOS was found in some intrapineal PHI‐ and VIP‐positive fibres. PHI‐, VIP‐ and NOS‐positive nerve fibres were more numerous in the peripheral than in the central part of the pineal. PACAP‐positive fibres were equally distributed within the gland. The density of SOM‐positive fibres was higher in the ventro‐proximal than in the dorso‐distal part of the pineal. SOM was also detected in some neuronal‐like cells or specialized pinealocytes situated in the central region of the gland. Two populations of fibres containing SP were found: CGRP‐positive, present in the distal and central parts of the pineal as well as CGRP‐negative, localized in the proximal compartment of the gland.