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.
Collage of Nursing, Yokohama City University School of Medicine, 3-9 Fukuura, 236-0004, Kanazawa-ku, Yokohama, Japan.
Midori
M
Tsukagoshi
Richard C
RC
Goris
Kengo
K
Funakoshi
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