Rovati L C, Sacerdote P, Fumagalli P, Bianchi M, Mantegazza P, Panerai A E
Department of Pharmacology, School of Medicine, University of Milano, Italy.
Pharmacol Biochem Behav. 1990 May;36(1):123-6. doi: 10.1016/0091-3057(90)90136-6.
Timing or intensity of shocks significantly modify the characteristics of the analgesia induced by footshock, and conditioning to footshock induces analgesia, independently from the time and shock parameters used for conditioning. However, whatever the parameters of shock, and the presence of conditioning or not, the stress has to be inescapable in order to produce an increase in pain thresholds. This observation suggests that anxiety plays a major role in the development of stress-induced analgesia. In order to test this hypothesis we investigated the effects of the benzodiazepine agonists diazepam and clonazepam, the antagonists RO 15-1788, CGS 8216, CGS 9896, and the inverse agonists FG 7142 and FG 7041 on the development and maintenance of stress-induced analgesia. Benzodiazepine receptor agonists decreased the analgesic effect of inescapable footshock, benzodiazepine receptor antagonists increased the footshock induced analgesia, whereas inverse agonists did not modify the analgesia induced by the shock. All the benzodiazepine receptor ligands blocked the antagonism of the footshock analgesia induced by naloxone.
电击的时间或强度会显著改变足部电击诱导的镇痛特征，而且对足部电击的条件作用会诱导镇痛，这与用于条件作用的时间和电击参数无关。然而，无论电击参数如何，以及是否存在条件作用，压力必须是无法逃避的才能使痛阈升高。这一观察结果表明，焦虑在应激诱导的镇痛作用的发展中起主要作用。为了验证这一假设，我们研究了苯二氮䓬类激动剂地西泮和氯硝西泮、拮抗剂RO 15 - 1788、CGS 8216、CGS 9896以及反向激动剂FG 7142和FG 7041对应激诱导的镇痛作用的发展和维持的影响。苯二氮䓬受体激动剂降低了无法逃避的足部电击的镇痛效果，苯二氮䓬受体拮抗剂增强了足部电击诱导的镇痛作用，而反向激动剂并未改变电击诱导的镇痛作用。所有苯二氮䓬受体配体都阻断了纳洛酮对足部电击镇痛的拮抗作用。
