Kavaliers Martin, Colwell Douglas D, Choleris Elena
Department of Psychology and Neuroscience Program, University of Western Ontario, London, Ontario N6A 5C2, Canada Agriculture and Agri-Food Canada, Box 3000 Main, Lethbridge, Alberta T1J 4B1, Canada Lawson Research Institute, St. Joseph's Health Centre, University of Western Ontario London, Ontario, N6A 5C1, Canada.
Pain. 1998 Aug;77(2):163-171. doi: 10.1016/S0304-3959(98)00092-X.
There is evidence for sex differences in responses to noxious stimuli and in the expression and mediation of analgesia. In particular, results of investigations with swim stress and the more ethologically appropriate stress of predator odor exposure have suggested sex differences in N-methyl-D-aspartate (NMDA) receptor system involvement in the mediation of analgesia. Whether or not this sex difference generalizes to other environmental stressors is, however, not clear. Biting flies are a natural aversive stimuli commonly encountered by wild and domestic animals and humans. The present study examined the opioid and non-opioid mediated nociceptive (50 degrees C hot plate) responses of reproductive male and female deer mice, Peromyscus maniculatus, exposed to biting fly attack. A 30 min exposure to biting flies (stable flies, Stomoxys calcitrans (L.)) elicited a naloxone sensitive, opioid-mediated analgesia that was of a greater magnitude in males than in female deer mice. In contrast, a 5 min exposure to biting flies elicited a 'on-opioid' analgesia that was of similar magnitude in both sexes and insensitive to both naloxone and the specific kappa opiate antagonist, nor-binaltorphimine. In male mice this non-opioid analgesia was antagonised by the competitive NMDA antagonist, NPC 1262, while in reproductive females the biting fly-induced analgesia was insensitive to NPC 12626. These results show that there are sex differences in NMDA involvement in the mediation of the non-opioid analgesia arising from brief exposure to the stress of biting fly attack. These data from a common, natural environmental challenge support the presence of basic sex difference in NMDA involvement in the mediation of stress-induced analgesia.
有证据表明，在对伤害性刺激的反应以及镇痛的表达和调节方面存在性别差异。特别是，关于游泳应激以及更符合行为学的捕食者气味暴露应激的研究结果表明，N-甲基-D-天冬氨酸（NMDA）受体系统在镇痛调节中的参与存在性别差异。然而，这种性别差异是否适用于其他环境应激源尚不清楚。叮咬苍蝇是野生动物、家畜和人类常见的一种自然厌恶刺激。本研究检测了暴露于叮咬苍蝇攻击下的成年雄性和雌性鹿鼠（白足鼠）的阿片类和非阿片类介导的伤害感受（50摄氏度热板）反应。暴露于叮咬苍蝇（厩螫蝇）30分钟会引发一种纳洛酮敏感的、阿片类介导的镇痛，雄性鹿鼠的镇痛程度大于雌性。相反，暴露于叮咬苍蝇5分钟会引发一种“非阿片类”镇痛，两性的镇痛程度相似，且对纳洛酮和特异性κ阿片拮抗剂 nor-binaltorphimine均不敏感。在雄性小鼠中，这种非阿片类镇痛被竞争性NMDA拮抗剂NPC 1262拮抗，而在成年雌性中，叮咬苍蝇诱导的镇痛对NPC 1262不敏感。这些结果表明，在短暂暴露于叮咬苍蝇攻击应激所产生的非阿片类镇痛调节中，NMDA的参与存在性别差异。这些来自常见自然环境挑战的数据支持了在NMDA参与应激诱导镇痛调节方面存在基本性别差异。
