title: Increased levels of GMAP, VIP and nitric oxide synthase, and their mRNAs, in lumbar dorsal root ganglia of the rat following systemic resiniferatoxin treatment.
abstract: Using in situ hybridization, the expression of mRNA encoding galanin, vasoactive intestinal polypeptide (VIP), neuropeptide Y (NPY), and nitric oxide synthase (NOS), respectively, was studied in lumbar dorsal root ganglia of rats given a single s.c. dose of 300 micrograms kg-1 resiniferatoxin (RTX), an ultrapotent capsaicin analogue. In control animals, 10% of the DRG neurones were positive for galanin mRNA, whereas no message for VIP, NPY or NOS could be detected. One week after RTX treatment, a markedly increased number (approximately 30%) of the neurones expressed galanin mRNA. Simultaneously, VIP and NOS mRNA became detectable in 6-8% of the neurones. The number of galanin-positive neurones declined after 2 weeks and returned to control levels by 8 weeks. The increase in number of VIP-, or NOS-positive neurones persisted up to 4 weeks after RTX treatment and declined thereafter. Also, there was a small increase in NPY mRNA-positive neurones. In parallel immunohistochemical experiments, similar increases were observed for galanin message-associated protein (GMAP)-, VIP- and NOS-like immunoreactivities. Our findings suggest that RTX can cause changes (messenger plasticity) in galanin, VIP and NOS expression in capsaicin-sensitive sensory neurones of the rat, similar to those described following axotomy.
authors.affiliation: Department of Physiology and Pharmacology, Karolinska Institute, Stockholm, Sweden.
authors.forename: T
authors.initials: T
authors.lastname: Farkas-Szallasi
authors.forename: J M
authors.initials: JM
authors.lastname: Lundberg
authors.forename: Z
authors.initials: Z
authors.lastname: Wiesenfeld-Hallin
authors.forename: T
authors.initials: T
authors.lastname: Hökfelt
authors.forename: A
authors.initials: A
authors.lastname: Szallasi
mesh_terms: D000818:Animals; D004224:Diterpenes / Q000494:pharmacology; D005260:Female; D019004:Galanin / Q000032:analysis*; D005727:Ganglia, Spinal / Q000187:drug effects* / Q000378:metabolism; D007150:Immunohistochemistry; D008161:Lumbosacral Region; D009498:Neurotoxins / Q000494:pharmacology; D019001:Nitric Oxide Synthase / Q000378:metabolism*; D010446:Peptide Fragments / Q000032:analysis*; D051381:Rats; D017207:Rats, Sprague-Dawley; D014660:Vasoactive Intestinal Peptide / Q000378:metabolism*
chemical_list: D004224:Diterpenes; D009498:Neurotoxins; D010446:Peptide Fragments; C078371:galanin message-associated peptide; D014660:Vasoactive Intestinal Peptide; D019004:Galanin; C024353:resiniferatoxin; D019001:Nitric Oxide Synthase