Robertson J A, Hough L B, Bodnar R J
Department of Psychology, Queens College, CUNY, Flushing 11367.
Pharmacol Biochem Behav. 1988 Sep;31(1):107-12. doi: 10.1016/0091-3057(88)90320-6.
Antagonism of the H-2 receptor with cimetidine and other histaminergic receptor antagonists has been used to differentiate nonopioid and opioid forms of footshock analgesia which are mediated by neural mechanisms. Cimetidine reduces nonopioid footshock analgesia while potentiating an opioid form of this analgesia. The present study examined whether cimetidine altered the nonopioid, neurohormonal analgesia induced by either continuous cold-water swims (CCWS: 2 degrees C for 3.5 min) or the opioid analgesia induced by intermittent cold-water swims (ICWS: 2 degrees C, 18 10-sec swims, 18 10-sec recovery periods). Vehicle or cimetidine (10, 50, 100 mg/kg) injections were administered alone or paired with either CCWS or ICWS; tail-flick latencies, jump thresholds and core body temperatures were then measured. Cimetidine (100 mg/kg) significantly potentiated CCWS and ICWS analgesia and hypothermia, while having minimal effects upon basal thresholds. Lower cimetidine doses produced transitory effects on these measures. These data demonstrate dissociations between neural and neurohormonal forms of nonopioid analgesia following cimetidine treatment. The latter effect may be attributed to changes in stress responsiveness or thermoregulation rather than pain inhibition.
西咪替丁和其他组胺能受体拮抗剂对H - 2受体的拮抗作用已被用于区分由神经机制介导的非阿片类和阿片类足部电击镇痛形式。西咪替丁可降低非阿片类足部电击镇痛作用，同时增强这种镇痛作用的阿片类形式。本研究考察了西咪替丁是否会改变由持续冷水游泳（CCWS：2℃，持续3.5分钟）诱导的非阿片类神经激素性镇痛，或由间歇性冷水游泳（ICWS：2℃，18次10秒游泳，18次10秒恢复期）诱导的阿片类镇痛。单独或与CCWS或ICWS配对给予载体或西咪替丁（10、50、100mg/kg）注射；然后测量甩尾潜伏期、跳跃阈值和核心体温。西咪替丁（100mg/kg）显著增强了CCWS和ICWS镇痛及体温过低，而对基础阈值影响最小。较低剂量的西咪替丁对这些指标产生短暂影响。这些数据表明西咪替丁治疗后非阿片类镇痛的神经和神经激素形式之间存在分离。后一种效应可能归因于应激反应性或体温调节的变化，而非疼痛抑制。
