Physiological role of the ascending monoaminergic system in hypothalamo-hypophysial responses to emotional stress

本文研究了单胺受体拮抗剂或苯二氮卓类药物对雄性Wistar大鼠产生焦虑的新刺激对恐惧刺激的神经内分泌反应的影响。1.多巴胺能D_1受体介导伤害性刺激的易化性加压素反应，而不是条件性恐惧刺激的抑制性加压素反应。2.缺氧的新环境刺激可抑制加压素的分泌。3.组胺能H_2受体介导新刺激的抑制性加压素反应，并以依赖活动的方式抑制易化性催产素的反应。4.去甲肾上腺素系统被证实中介加压素的反应。对条件性恐惧刺激的催产素和催乳素的分泌，但对非条件性恐惧刺激或引起焦虑的新环境刺激的反应不起作用。5.氯氮卓酮，一种已知通过调节去甲肾上腺素能神经元活动而改善焦虑状态的苯二氮卓类药物，被发现阻止加压素和催产素分泌对无条件或条件性恐惧刺激的反应，但不阻止对产生焦虑的新环境刺激的反应。6.5-羟色胺能5-羟色胺；1A&gt；受体被证实参与加压素和催产素对条件性恐惧刺激的反应，但不参与对新刺激的反应。

Effects of monoaminergic receptor antagonists or a benzodiazepine were studied on neuroendocrine responses to fear stimuli of anxiety-producing novel stimuli in male Wistar rats.1.Dopaminergic D1 receptors were found to mediate facilitatory vasopressin response to noxious stimuli but not the suppressive vasopressin response to conditioned fear stimuli.2.Anxiogenic novel environmental stimuli were shown to suppress vasopressin secretion.3.Histaminergic H2 receptors were shown to mediate the suppressive vasopressin response to novel stimuli and to inhibit, in an activity-dependent manner, the facilitatory oxytocin response to the stimuli.4.The noradrenergic system was demonstrated to mediate the responses in vasopressin, oxytocin and prolactin secretion to conditioned fear stimuli but not to the responses to unconditioned fear stimuli or anxiogenic novel environmental stimuli.5.Chlordiazepoxide, one of the benzodiazepines which are known to ameliorate an anxiety state as a result of modulating noradrenergic neuron activity, was found to block the responses in vasopressin and oxytocin secretion to unconditioned or conditioned fear stimuli but not the responses to anxiety-producing novel environmental stimuli.6.Serotonergic 5-HT_<1A> receptors were demonstrated to be involved in the vasopressin and oxytocin responses to conditioned fear stimuli but not to novel stimuli.