Miaskowski C, Levine J D
School of Nursing, University of California, San Francisco 94143.
Brain Res. 1992 Nov 20;596(1-2):41-5. doi: 10.1016/0006-8993(92)91530-r.
The effect of intracerebroventricular administration of a selective mu- (CTOP) or delta- (ICI 174,864) opioid receptor antagonist on the antinociceptive effects produced by intrathecal administration of selective mu- (DAMGO), delta- (DPDPE) and kappa- (U50-488H) opioid receptor agonists was evaluated using the Randall-Selitto paw-withdrawal test, in the rat. While the intracerebroventricular administration of CTOP or ICI 174,864, alone, had no effect on nociceptive thresholds, intracerebroventricular administration of CTOP and ICI 174,864 produced marked antagonism of the antinociceptive effects of intrathecal DAMGO. The antinociceptive effects of intrathecal administration of DPDPE or U50,488H were not antagonized by intracerebroventricular administration of CTOP or ICI 174,864. These data suggest that, in the rat, along with the established descending antinociceptive pathways, there is an ascending antinociceptive control mechanism projecting from the spinal cord to the brainstem. The ascending antinociceptive control involves mu- and delta-opioid agonism at supraspinal sites and appears to be mediated selectively by mu-, but not by delta- or kappa-opioid agonism at the spinal level.
采用Randall-Selitto paw-withdrawal试验，在大鼠中评估了脑室内注射选择性μ-（CTOP）或δ-（ICI 174,864）阿片受体拮抗剂对鞘内注射选择性μ-（DAMGO）、δ-（DPDPE）和κ-（U50-488H）阿片受体激动剂所产生的抗伤害感受作用的影响。虽然单独脑室内注射CTOP或ICI 174,864对伤害感受阈值没有影响，但脑室内注射CTOP和ICI 174,864可显著拮抗鞘内注射DAMGO的抗伤害感受作用。脑室内注射CTOP或ICI 174,864不能拮抗鞘内注射DPDPE或U50,488H的抗伤害感受作用。这些数据表明，在大鼠中，除了已确立的下行抗伤害感受通路外，还存在一条从脊髓投射到脑干的上行抗伤害感受控制机制。上行抗伤害感受控制涉及脊髓以上部位的μ-和δ-阿片激动作用，并且似乎在脊髓水平上选择性地由μ-阿片激动作用介导，而不是由δ-或κ-阿片激动作用介导。
