Ryan S M, Maier S F
Department of Psychology, University of Colorado, Boulder 80309.
Behav Neurosci. 1988 Jun;102(3):371-80. doi: 10.1037//0735-7044.102.3.371.
In this article we investigate the impact of estrous cycle, ovariectomy, and estrogen replacement on both opioid and nonopioid stress-induced analgesia. Stage of estrous strongly influenced analgesia. Diestrus females exhibited the typical male pattern produced by the analgesia inducing procedures used--strong nonopioid analgesia following 10-20 tailshocks, and strong opioid analgesia following 80-100 tailshocks. In these experiments the nonopioid analgesia was slightly attenuated during estrus, but the opioid analgesia was markedly reduced. The role of estrogen in producing these changes was studied with estrogen replacement in ovariectomized subjects. Ovariectomy only slightly altered nonopioid analgesia but eliminated opioid analgesia, which suggests that some estrogen might be necessary to maintain the integrity of the system(s) underlying opioid analgesia. Estrogen administration restored opioid analgesia, but further estrogen suppressed opioid analgesia, duplicating the estrus pattern. It did not suppress nonopioid analgesia. Opioid analgesia was enhanced 102 hr after estrogen replacement, thus duplicating the diestrus pattern. Estrogen thus appears to be responsible for the impact of estrous cycle on opioid but not on nonopioid analgesia. These results suggest that ovarian hormones may modulate the impact of stressors on endogenous pain inhibition and other stress-responsive systems.
在本文中，我们研究了发情周期、卵巢切除术和雌激素替代对阿片类和非阿片类应激诱导镇痛的影响。发情阶段对镇痛有强烈影响。动情后期的雌性表现出所用镇痛诱导程序产生的典型雄性模式——10 - 20次尾部电击后产生强烈的非阿片类镇痛，80 - 100次尾部电击后产生强烈的阿片类镇痛。在这些实验中，发情期非阿片类镇痛略有减弱，但阿片类镇痛明显降低。通过对去卵巢受试者进行雌激素替代研究了雌激素在产生这些变化中的作用。卵巢切除术仅轻微改变了非阿片类镇痛，但消除了阿片类镇痛，这表明某些雌激素可能是维持阿片类镇痛基础系统完整性所必需的。给予雌激素可恢复阿片类镇痛，但进一步给予雌激素会抑制阿片类镇痛，重现发情期模式。它并未抑制非阿片类镇痛。雌激素替代102小时后阿片类镇痛增强，从而重现了动情后期模式。因此，雌激素似乎是发情周期对阿片类而非非阿片类镇痛产生影响的原因。这些结果表明，卵巢激素可能调节应激源对内源性疼痛抑制和其他应激反应系统的影响。
