ANTINOCICEPTIVE RESPONSES PRODUCED BY HUMAN PUTATIVE COUNTERPART OF NOCISTATIN

b-nocistatin is a heptadecapeptide produced from bovine prepronocicept in and blocks the induction of hyperalgesia and touch-evoked pain (all odynia) by intrathecal administration of nociceptin or prostaglandin E -2 (PGE(2)). Human prepronociceptin may generate a 30-amino acid pepti de different in length from b-nocistatin. Here, we examine whether the human putative counterpart of nocistatin (h-nocistatin) possessed the same biological activities as b-nocistatin. Simultaneous intrathecal injection of h-nocistatin in mice blocked the induction of allodynia b y nociceptin and PGE(2) in a dose-dependent manner with ID50 values of 329 pg kg(-1) and 16.6 ng kg(-1), respectively. h-nocistatin was abou t 10 times less potent than b-nocistatin, h-nocistatin also attenuated the nociceptin- and PGE(2)-induced hyperalgesia. These results demons trate that h-nocistatin is biologically active and may be involved in the processing of pain at the spinal level in humans.