Differential distribution of vanilloid receptors in the primary sensory neurons projecting to the dorsal skin and muscles.
We examined transient receptor potential (TRP) V1 and TRPV2 expression in calcitonin gene-related peptide (CGRP) positive (+) primary sensory neurons projecting to the skin and skeletal muscles of the rat dorsum. Among the dorsal root ganglia at the levels from C2 to Th1, 34.9% of neurons projecting to the skin were positive for CGRP, and 32.6% or 21.6% of neurons projecting to the trapezius muscle or the longissimus muscle were positive for CGRP. Of the small CGRP+ neurons projecting to the skin, 53.5% were positive for TRPV1, 11.6% were positive for TRPV2. Of the small CGRP+ neurons projecting to the trapezius or the longissimus, 53.1 or 53.2% were positive for TRPV1, 8.8 or 8.3% were positive for TRPV2, respectively. In the periphery, 29.3% of CGRP+ nerve fibers were positive for TRPV1 in the skin, whereas 65.0 or 59.8% were positive in the trapezius or the longissimus. Therefore, the present study showed that the percentage of CGRP+ neurons projecting to the trapezius is higher than that to the longissimus, and that the co-localization percentage of CGRP and TRPV1 on the sensory nerves was also higher in the trapezius than in the longissimus and the skin.
Tsukagoshi
Midori
M
Collage of Nursing, Yokohama City University School of Medicine, 3-9 Fukuura, 236-0004, Kanazawa-ku, Yokohama, Japan.
Goris
Richard C
RC
Funakoshi
Kengo
K
D000578:Amidines / Q000737:chemistry; D000818:Animals; D005456:Fluorescent Dyes / Q000737:chemistry; D005727:Ganglia, Spinal / Q000378:metabolism; D007150:Immunohistochemistry; D008297:Male; D018482:Muscle, Skeletal / Q000294:innervation* / Q000378:metabolism; D009412:Nerve Fibers / Q000378:metabolism; D009475:Neurons, Afferent / Q000378:metabolism*; D051381:Rats; D017208:Rats, Wistar; D018015:Receptors, Calcitonin Gene-Related Peptide / Q000378:metabolism; D012867:Skin / Q000294:innervation* / Q000378:metabolism; D050916:TRPV Cation Channels / Q000378:metabolism*; D014018:Tissue Distribution
D000578:Amidines; D005456:Fluorescent Dyes; D018015:Receptors, Calcitonin Gene-Related Peptide; D050916:TRPV Cation Channels; C493922:Trpv1 protein, rat; C476722:Trpv2 protein, rat; C031455:diamidino compound 253-50