title: [Effect of CGRP receptor antagonist CGRP8-37 on nociceptive response, NOS expression and NO content in the dorsal horn of spinal cord during formalin-induced inflammatory pain in rats].
abstract: OBJECTIVE
  To study the effect of CGRP receptor antagonist CGRP8-37 on nociceptive response and expression of nitric oxide synthase (NOS) and content of nitric oxide (NO) in the dorsal horn of the spinal cord of rats during formalin-induced inflammatory pain.
  
  
  METHODS
  Using formalin injection into right hind paw induced inflammatory pain. Counting the times of flinching reflex was used to observe the degree of spontaneous pain. NADPH-d histochemistry was used to observe the changes of NOS expression. The content of NO was observed by measuring the contents of nitrate/nitrite (NO3- / NO2-).
  
  
  RESULTS
  spontaneous pain behavioral was elicited by formalin injection. The NOS expression and NO content significantly increased in the spinal cord at 24 h after formalin injection. Intrathecal injection of CGRP8-37 could significantly inhibit the response of spontaneous pain and the increases of NOS expression and NO content induced by formalin injection.
  
  
  CONCLUSIONS
  The activation of CGRP receptors enhances NOS expression and NO production in the dorsal horn of the spinal cord during formalin-induced inflammatory pain.
authors.affiliation: Department of Pathophysiology, Institute of Basic Medicine, Hebei Medical University, Shijiazhuang 050017, China.
authors.forename: Tong-nan
authors.initials: TN
authors.lastname: Li
authors.forename: Qing-jun
authors.initials: QJ
authors.lastname: Li
authors.forename: Wen-bin
authors.initials: WB
authors.lastname: Li
authors.forename: Xiao-cai
authors.initials: XC
authors.lastname: Sun
authors.forename: Shu-qin
authors.initials: SQ
authors.lastname: Li
mesh_terms: D000818:Animals; D015740:Calcitonin Gene-Related Peptide / Q000494:pharmacology*; D000077221:Calcitonin Gene-Related Peptide Receptor Antagonists; D005557:Formaldehyde / Q000009:adverse effects; D009569:Nitric Oxide / Q000378:metabolism*; D019001:Nitric Oxide Synthase / Q000378:metabolism*; D010146:Pain / Q000139:chemically induced / Q000378:metabolism*; D010446:Peptide Fragments / Q000494:pharmacology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D013116:Spinal Cord / Q000187:drug effects* / Q000378:metabolism
chemical_list: D000077221:Calcitonin Gene-Related Peptide Receptor Antagonists; D010446:Peptide Fragments; C058636:calcitonin gene-related peptide (8-37); D005557:Formaldehyde; D009569:Nitric Oxide; D019001:Nitric Oxide Synthase; D015740:Calcitonin Gene-Related Peptide