Budget Amount *help |
¥2,000,000 (Direct Cost: ¥2,000,000)
Fiscal Year 1994: ¥1,000,000 (Direct Cost: ¥1,000,000)
Fiscal Year 1993: ¥1,000,000 (Direct Cost: ¥1,000,000)
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Research Abstract |
1)Intrathecal (i.t.) injection of substance P (SP) in mice produced a series of scratching, bitting and licking (SBL) behavioral response. 2)I.t.injection of SP (1-7), an N-terminal SP fragment, reduced SP-induced SBL response. 3)Similar effects were observed by SP (1-7) analogues, [D-Arg^1]SP (1-7), [D-Arg^1, D-Pr^2] SP (1-7), [D-Arg^1, D-Trp^7] SP (1-7) and [Tyr^0, D-Arg^1, D-Pro^<2,4>] SP (1-7). 4)I.t.SP (1-7) and its analogues produced antinociceptive effects as assayd by the capsaicin test. 5)SP (1-7) was also effective on N-methyl-D-aspartate (NMDA)-induced SBL behavioral response, which was reduced by i.t.methylene blue (MB), but not by pretreatment with L-arginine. 6)The effect of MB on the NMDA-induced response was reserved by co-injection of cyclic-GMP.These results suggest that the inhibitory effect of SP (1-7) on the NMDA respose may be involved in increased amount of cyclic-GMP,which is not mediated through nitric oxide system in the mouse spinal cord.
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