The journal of pain : official journal of the American Pain Society
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Pretreatment with intraperitoneal (i.p.) indomethacin was used to determine whether indomethacin preferentially affected the development of edema and hyperalgesia to thermal and mechanical stimuli produced by injection of zymosan in the ispsilateral hindpaw of the rat. Indomethacin also was delivered intrathecally (i.t.) either 30 minutes before or 4 hours after intraplantar zymosan to determine whether spinal prostaglandin production was important for the induction and/or maintenance of hyperalgesia. Zymosan alone produced a robust edema, a monophasic mechanical hyperalgesia, and a biphasic thermal hyperalgesia in the ipsilateral hindpaw. ⋯ Once hyperalgesia was established, i.t. indomethacin also attenuated the mechanical hyperalgesia whereas it had no effect on thermal hyperalgesia or edema. These data suggest that peripheral, but not spinal prostaglandins contribute to the edema and development of thermal hyperalgesia produced by zymosan. In contrast, spinal prostaglandins contribute to the development and maintenance of mechanical hyperalgesia.