MECHANISMS OF REFERRED VISCERAL PAIN - UTERINE INFLAMMATION IN THE ADULT VIRGIN RAT RESULTS IN NEUROGENIC PLASMA EXTRAVASATION IN THE SKIN

The purpose of this study was to investigate the mechanisms of referre d pain observed in female patients with pain from the reproductive org ans. We developed a model of inflammatory uterine pain in the rat. Inf lammation of the uterus in rats pretreated with Evans Blue Dye resulte d in dye extravasation in the skin over the abdomen, groin, lower back , thighs, perineal area and proximal tail, thus providing for the firs t time evidence for the trophic changes observed in the area of referr ed visceral pain in an animal model of uterine pain. The neuronal path ways mediating the observed dye extravasation in the skin after uterin e inflammation may include dichotomizing afferent fibers, afferent-aff erent interactions via a spinal cord pathway or a sympathetic reflex. This model will allow to gain further insight into the mechanisms of r eferred pain and the trophic changes observed in the area of referred pain in visceral disease. (C) 1997 International Association for the S tudy of Pain. Published by Elsevier Science B.V.