Immunohistochemical localisation of regulatory neuropeptides in human circumvallate papillae.
The occurrence and distribution of neuropeptide-containing nerve fibres in the human circumvallate papillae were examined by the peroxidase-antiperoxidase immunolocalisation method using surgical specimens that had not been subjected to radiotherapy, and the abundance of neuropeptide-containing fibres was expressed as the percentage of total nerve fibres demonstrated by protein gene product (PGP) 9.5 immunoreactivity for a quantitative representation of these peptidergic fibres. Substance P (SP) and calcitonin gene-related peptide (CGRP) immunoreactive (IR) nerve fibres were densely distributed in the connective tissue core of the circumvallate papillae, and some SP and CGRP-IR fibres were associated with the taste buds. A moderate number of vasoactive intestinal polypeptide (VIP)-IR fibres and a few galanin (GAL)-IR fibres were also seen in the connective tissue core and subepithelial layer. There were, however, no VIP-IR or GAL-IR fibres associated with the taste buds. Neuropeptide Y (NPY)-IR fibres were few and were associated with the blood vessels. Within the epithelium of the circumvallate papillae, no peptidergic fibres were found, although a number of PGP 9.5-IR fibres were detected. The abundance of SP, CGRP, VIP, and GAL-IR fibres expressed as the percentage of total PGP 9.5 IR fibres was 25.35+/-3.45%, 22.18+/-3.26%, 10.23+/-1.18%, and 4.12+/-1.05%, respectively. The percentage of NPY-IR fibres was below 3%. In a deeper layer of the papillae, a few VIP, GAL, and NPY-IR ganglion cells were found, and VIP immunoreactivity was detected in a few cells of the taste buds. There was no somatostatin, leucine enkephalin, or methionine enkephalin immunoreactivity in the circumvallate papillae. These results suggest that the dense SP and CGRP-IR fibres within the connective tissue core of the human circumvallate papillae may be involved in the deep sensation of the tongue.
Department of Anatomy, Yokohama City University School of Medicine, Yokohama, Japan. tatsumik@med.yokohama-cu.ac.jp
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T
Kusakabe
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H
Matsuda
Y
Y
Gono
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M
Furukawa
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Hiruma
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Kawakami
M
M
Tsukuda
T
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Takenaka
D000328:Adult; D000368:Aged; D015415:Biomarkers / Q000032:analysis; D015740:Calcitonin Gene-Related Peptide / Q000032:analysis; D019004:Galanin / Q000032:analysis; D006801:Humans; D007124:Immunoenzyme Techniques; D008297:Male; D008875:Middle Aged; D009412:Nerve Fibers / Q000737:chemistry* / Q000648:ultrastructure; D009478:Neuropeptide Y / Q000032:analysis; D009479:Neuropeptides / Q000032:analysis*; D013373:Substance P / Q000032:analysis; D013650:Taste Buds / Q000737:chemistry; D013869:Thiolester Hydrolases / Q000032:analysis; D014059:Tongue / Q000737:chemistry* / Q000294:innervation*; D043222:Ubiquitin Thiolesterase; D014660:Vasoactive Intestinal Peptide / Q000032:analysis
D015415:Biomarkers; D009478:Neuropeptide Y; D009479:Neuropeptides; D013373:Substance P; D014660:Vasoactive Intestinal Peptide; D019004:Galanin; D013869:Thiolester Hydrolases; D043222:Ubiquitin Thiolesterase; D015740:Calcitonin Gene-Related Peptide