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Tachykinins and tachykinin‐receptors in the rat pineal gland
Author(s) -
Mukda S.,
Chetsawang B.,
Govitrapong P.,
Schmidt P. T.,
HaySchmidt A.,
Møller M.
Publication year - 2005
Publication title -
european journal of neuroscience
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.346
H-Index - 206
eISSN - 1460-9568
pISSN - 0953-816X
DOI - 10.1111/j.1460-9568.2005.04088.x
Subject(s) - neurokinin a , tachykinin receptor , substance p , pinealocyte , receptor , pineal gland , in situ hybridization , immunohistochemistry , neurokinin b , microbiology and biotechnology , biology , messenger rna , chemistry , pathology , endocrinology , neuropeptide , immunology , melatonin , biochemistry , medicine , gene
High‐pressure liquid chromatography of extracts of rat pineal glands, followed by radio immunological analysis with antibodies against tachykinins, demonstrated the presence of substance P, neurokinin A and neurokinin B in the superficial rat pineal gland. Immunohistochemistry on perfusion‐fixed rat brain sections showed substance P and neurokinin A to be present in nerve fibers located both in the perivascular spaces as well as intraparenchymally between the pinealocytes. After extracting total RNA, followed by reverse transcription and polymerase chain reaction amplification with primers specific for NK 1 ‐, NK 2 ‐ and NK 3 ‐receptors, agarose gel analysis of the reaction products showed the presence of mRNA encoding all three neurokinin receptors. Immunohistochemical analysis showed NK 1 receptor to be located in the interstitial cells of the gland. This location was confirmed by use of in situ hybridization using radioactively labeled antisense oligonucleotide probes. Double immunohistochemical stainings showed that the NK 1 ‐immunoreactive cells were not a part of the macrophages or antigen‐presenting cells of the gland. Our study suggests that tachykinins, after release from intrapineal nerve fibers, are involved in an up to now unknown function, different from that of melatonin synthesis.