Strain differences in pain sensitivity and expression of preprodynorphin mRNA in rats following peripheral inflammation.
The experience of pain is highly variable among individuals, which may be due in part to the effects of genetic factors on the central transmission and modulation of noxious inputs. This study examined behavioral responses and the expression of preprodynorphin (PPD) mRNA at the spinal level during complete Freund's adjuvant-induced inflammation of the unilateral hind paw in male Fischer 344 (F344), Sprague-Dawley (SD), and Lewis (LEW) rats. Experiments showed that F344 rats exhibited stronger hind paw hyperalgesia and greater spinal PPD mRNA induction than SD or LEW rats. These results indicate that genetic factors that determine the spinal PPD mRNA and dynorphin production underlie strain-dependent differences in pain perception.
Zhang
Rui-Xin
RX
Center for Integrative Medicine, School of Medicine, University of Maryland, Baltimore, MD 21201, USA. rzhan001@umaryland.edu
Lao
Lixing
L
Qiao
Jian-Tian
JT
Ruda
Mary Ann
MA
D000818:Animals; D001522:Behavior, Animal; D015152:Blotting, Northern; D004399:Dynorphins / Q000235:genetics / Q000378:metabolism*; D005620:Freund's Adjuvant; D007249:Inflammation / Q000139:chemically induced; D008297:Male; D017288:Pain Threshold / Q000502:physiology*; D010523:Peripheral Nervous System Diseases / Q000139:chemically induced / Q000378:metabolism* / Q000503:physiopathology; D011498:Protein Precursors / Q000235:genetics / Q000378:metabolism*; D012333:RNA, Messenger / Q000378:metabolism; D051381:Rats; D011916:Rats, Inbred F344; D011917:Rats, Inbred Lew; D017207:Rats, Sprague-Dawley; D013045:Species Specificity; D013116:Spinal Cord / Q000378:metabolism / Q000503:physiopathology; D013997:Time Factors
D011498:Protein Precursors; D012333:RNA, Messenger; C036448:pre-prodynorphin; D004399:Dynorphins; D005620:Freund's Adjuvant