Increased response of hypogastric nerve fibers to bradykinin by mustard oil-induced uterine inflammation in the rat

It is well known that the inflammation of somatic tissues, bladder and colon can alter the sensitivity of primary afferents innervating these tissues. To see if uterine afferents also show altered sensitivity, we examined their responses to the algesic agent bradykinin before and after induction of uterine inflammation. Inflammation was induced by injecting the mustard oil into the uterine lumen of adult female rats. After induction of inflammation, the response latency to bradykinin did not change, but the duration and peak of the response and integrated impulse discharges during the response period increased significantly. Furthermore, after inflammation, the level of resting discharges of the afferents was much higher. These results are consistent with the idea that the inflammation can sensitize the uterine afferents.