title: Sex and hormonal variations in the development of at-level allodynia in a rat chronic spinal cord injury model.
abstract: The development of central neuropathic pain varies among patients with spinal cord injury (SCI). The factors contributing to the development and perpetuation of segmental pain (at-level allodynia) has been the focus of ongoing experiments in our laboratory. One such factor is hormonal status. We have shown previously, using a male rat model of SCI, that a severe contusion injury is necessary for the development of allodynia in trunk regions at and just above the level of a T8 injury. In this study, we examined at-level sensitivity for SCI ovariectomized (ovx) and cycling female rats as well as for SCI males implanted with either a placebo pellet or one that slowly releases 17beta-estradiol. The proportion of ovx SCI female rats and placebo-treated SCI males displaying pain-like behaviors to touch/pressure of at-level dermatomes up to 6 weeks post-injury (67% and 75%, respectively) was similar to our previous studies on SCI males (69%). In contrast, significantly fewer cycling SCI female rats and 17beta-estradiol treated SCI male rats showed sensitivity to touch at-level (26% and 30%, respectively). These results implicate 17beta-estradiol as a potential target that can readily be modulated to prevent segmental pain following SCI.
authors.affiliation: Department of Anatomical Sciences & Neurobiology, University of Louisville, Louisville, KY 40292, USA. chhubs01@louisville.edu
authors.forename: Charles H
authors.initials: CH
authors.lastname: Hubscher
authors.forename: Jason D
authors.initials: JD
authors.lastname: Fell
authors.forename: Daya S
authors.initials: DS
authors.lastname: Gupta
mesh_terms: D000818:Animals; D002908:Chronic Disease; D004958:Estradiol / Q000494:pharmacology / Q000502:physiology*; D004971:Estrus; D005260:Female; D006930:Hyperalgesia / Q000503:physiopathology*; D008297:Male; D010052:Ovariectomy; D011312:Pressure; D051381:Rats; D017208:Rats, Wistar; D012737:Sex Factors; D013119:Spinal Cord Injuries / Q000378:metabolism* / Q000503:physiopathology*; D014110:Touch
chemical_list: D004958:Estradiol