title: [Role of transient receptor potential melastatin 8 channels in migraine mechanism in rats].
abstract: OBJECTIVE
  To investigate the role of transient receptor potential melastatin 8 (TRPM8) channels in migraine mechanism in rats by measuring the changes in expression of TRPM8 in the trigeminal nerve of rats with migraine.
  
  
  METHODS
  Twenty male Sprague-Dawley rats were randomly and equally divided into a blank control group and a model group. Nitroglycerin (10 mg/kg) was injected subcutaneously in the back of the neck once a week for 5 weeks, to prepared a rat model of migraine without aura. Normal saline was injected subcutaneously instead of nitroglycerin in the control group. At 4 hours after the final injection, behavior scoring of all rats was performed, and then the trigeminal nerve ganglions of rats in both groups were collected for measurement of expression of N-methyl-D-aspartate receptor (NMDAR), protein kinase A (PKA), and TRPM8 using immunohistochemical staining, immunofluorescence, and Western blot, respectively.
  
  
  RESULTS
  The behavior score in each week during the rat model preparing was significantly higher in the model group than in the control group (P<0.05). The expression of NMDAR, PKA, and TRPM8 in the model group was significantly higher than in the control group (P<0.01). Both the behavior score and the expression of NMDAR were positively correlated with the expression of TRPM8 (r=0.822 and 0.794 respectively; P<0.01).
  
  
  CONCLUSIONS
  TRPM8 may be involved in migraine mechanism probably by activation of the NMDAR pathway.
authors.affiliation: Sichuan Academy of Medical Sciences and Sichuan Provincial People's Hospital, Chengdu 610072, China. mufaguang@163.com.
authors.forename: Dong-Mei
authors.initials: DM
authors.lastname: Qin
authors.forename: Zhuan
authors.initials: Z
authors.lastname: Zou
authors.forename: Chao-Ran
authors.initials: CR
authors.lastname: Zhou
authors.forename: Fa-Guang
authors.initials: FG
authors.lastname: Mu
mesh_terms: D000818:Animals; D017868:Cyclic AMP-Dependent Protein Kinases / Q000032:analysis; D008297:Male; D008881:Migraine Disorders / Q000209:etiology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D016194:Receptors, N-Methyl-D-Aspartate / Q000032:analysis / Q000502:physiology; D050053:TRPM Cation Channels / Q000502:physiology*
chemical_list: D016194:Receptors, N-Methyl-D-Aspartate; D050053:TRPM Cation Channels; C498947:Trpm8 protein, rat; D017868:Cyclic AMP-Dependent Protein Kinases