Department of Normal, Pathological and Clinical Physiology, Third Faculty of Medicine, Charles University in Prague, Prague, Czech Republic.
Physiol Res. 2012;61(Suppl 2):S139-47. doi: 10.33549/physiolres.932428.
Prenatal exposure to methamphetamine (METH) increases nociceptive sensitivity in adult rats. As the strong analgesics have high abuse potential and drugs of abuse are known to have analgesic properties, the aim was to study analgesic effect of different psychostimulants in control and prenatally METH-exposed rats. Latencies of withdrawal reflexes of hind limbs and the tail on thermal nociceptive stimuli were repeatedly measured in 15-min intervals after the application of 5 mg/kg s.c. of amphetamine (AMPH), methamphetamine (METH), cocaine (COC), 3,4-methylenedioxymethamphetamine (MDMA) or morphine (MOR). In all groups, AMPH induced on hind limbs stronger analgesia than METH and MDMA whereas COC and MOR were practically without any effect. On the tail, effect of AMPH did not differ from that of MOR. All psychostimulants increased defecation in comparison with MOR and in all groups the number of defecation boluses positively correlated with analgesia of the hind limbs. We did not confirm that prenatal exposure to METH makes adult rats more sensitive either to same drug or to other psychostimulants. The different analgesic potencies of psychostimulants and MOR at different body sites indicate the possible existence of a somatotopic organization of pain inhibition, which is controlled by different mechanisms.
产前暴露于甲基苯丙胺（METH）会增加成年大鼠的痛觉敏感性。由于强效阿片类药物具有高度滥用潜力，且已知滥用药物具有镇痛特性，因此本研究旨在探讨不同精神兴奋剂对对照组和产前 METH 暴露大鼠的镇痛作用。在皮下给予 5mg/kg 的安非他命（AMPH）、甲基苯丙胺（METH）、可卡因（COC）、3,4-亚甲二氧基甲基苯丙胺（MDMA）或吗啡（MOR）后，每隔 15 分钟重复测量后腿和尾巴对热痛觉刺激的退缩反射潜伏期。在所有组中，AMPH 对后腿的镇痛作用均强于 METH 和 MDMA，而 COC 和 MOR 几乎没有任何作用。在尾巴上，AMPH 的作用与 MOR 没有区别。所有精神兴奋剂均与 MOR 相比增加了排便，并且在所有组中，排便次数与后腿的镇痛作用呈正相关。我们没有证实产前暴露于 METH 会使成年大鼠对相同药物或其他精神兴奋剂更敏感。精神兴奋剂和 MOR 在不同身体部位的不同镇痛效力表明，疼痛抑制可能存在躯体组织化，而这种抑制由不同的机制控制。
