The major histocompatibility complex genes are associated with basal pain sensitivity differences between Dark-Agouti and novel congenic DA.1U rats.
OBJECTIVE
To investigate whether MHC genes are associated with basal pain sensitivity differences in Dark-Agouti (DA) rats and a novel congenic inbred DA.1U rats, whose genetic background is the same as DA rats except for major histocompatibility complex (MHC) genes.


METHODS
Mechanical withdrawal threshold (MWT) and heat withdrawal latencies (HWL) were compared in the two rat strains to reflect basal pain sensitivity. Immunohistochemistry was used to observe the expression level of RT1B, representative of MHC class II DQ region, and the basal expression of phosphorylated cAMP response element-binding protein (pCREB) in the L4/L5 spinal cord in the two rat strains.


RESULTS
The MWT and HWL of DA rats were significantly less than that of DA.1U rats. The expression level of pCREB in the L4/L5 spinal cord in DA rats was greater than that found in DA.1U rats. The expression level of RT1B in the spinal cord was greater in DA rats, which suggested MHC class II DQ region is likely involved in the differences in sensitivity to noxious mechanical and thermal stimulation between the two rat strains.


CONCLUSIONS
These results suggest MHC genes are associated with basal pain sensitivity, which may contribute to the identification of pain sensitivity and/or individually tailored pain treatment regimens.
Guo
Yuan
Y
Department of Physiology and Pathophysiology, Xi'an Jiaotong University School of Medicine, Xi'an, Shaanxi 710061, PR China.
Yao
Fanrong
F
Lu
Shemin
S
Cao
Dong-Yuan
DY
Reed
William R
WR
Zhao
Yan
Y
D000818:Animals; D020296:Animals, Congenic; D017362:Cyclic AMP Response Element-Binding Protein / Q000378:metabolism; D000949:Histocompatibility Antigens Class II / Q000378:metabolism; D006358:Hot Temperature; D008285:Major Histocompatibility Complex / Q000235:genetics*; D008297:Male; D010146:Pain / Q000235:genetics*; D017288:Pain Threshold; D010766:Phosphorylation; D020671:Posterior Horn Cells / Q000378:metabolism / Q000473:pathology; D051381:Rats; D011930:Reaction Time; D013045:Species Specificity
D017362:Cyclic AMP Response Element-Binding Protein; D000949:Histocompatibility Antigens Class II