Sensitizing effects of leukotriene B4 on intradental primary afferents.

Previous studies have established that leukotriene B4 (LTB4) sensitizes cutaneous nociceptors. In this study the effects of LTB4 on spontaneous and stimulus-evoked nerve activity from primary afferents innervating the dentin of canines in adult cats were examined. LTB4 treatment (25 micrograms/ml) significantly enhanced stimulus-evoked intradental nerve activity (INA) for at least 20 min after the removal of the compound from the recording preparation. Teeth treated with LTB4 demonstrated enhanced spontaneous nerve activity following the removal of hypertonic saline used to evoked INA. These findings provide additional evidence that LTB4 is able to sensitize nociceptors and may be a long-lasting hyperalgesic factor which may contribute to pain of pulpal origin.