Carter D A, Lightman S L
Medical Unit, Charing Cross and Westminster Medical School, Westminster Hospital, London, UK.
Neuroendocrinology. 1987 Dec;46(6):532-7. doi: 10.1159/000124876.
The plasma oxytocin (OT) response to acute stress was compared between virgin, lactating, and hyperprolactinaemic female rats. In virgin rats, brief immobilization was associated with a significant elevation of plasma OT to 24.7 +/- 3.7 pmol/l compared with 7.7 +/- 1.1 pmol/l in controls. In contrast, the stress response was absent in lactating (6 days post-partum) animals: control OT 9.4 +/- 2.2, immobilized OT 9.0 +/- 1.1 pmol/l. Hyperprolactinaemia produced by treatment with either dopamine antagonists (domperidone or haloperidol) or ovine prolactin was also associated with an impairment of the OT stress response in intact females, whereas domperidone treatment failed to modify the response in ovariectomized (OVX) rats. Following ovarian steroid replacement with oestradiol and progesterone, the inhibitory effect of domperidone was observed in OVX rats: control OT 11.1 +/- 2.5, immobilized OT 16.0 +/- 3.7 pmol/l. Treatment of OVX rats with oestradiol and progesterone, either separately or combined, did not modify the OT stress response. Plasma levels of vasopressin were not significantly modified in either control or immobilized rats of any experimental groups. The results indicate that hyperprolactinaemia may be a causative factor in the impairment of OT stress responses observed in lactating rats.
比较了未孕、泌乳和高催乳素血症雌性大鼠对急性应激的血浆催产素（OT）反应。在未孕大鼠中，短暂固定与血浆OT显著升高有关，升至24.7±3.7 pmol/l，而对照组为7.7±1.1 pmol/l。相比之下，泌乳（产后6天）动物不存在应激反应：对照组OT为9.4±2.2，固定组OT为9.0±1.1 pmol/l。用多巴胺拮抗剂（多潘立酮或氟哌啶醇）或羊催乳素治疗产生的高催乳素血症也与完整雌性动物的OT应激反应受损有关，而多潘立酮治疗未能改变去卵巢（OVX）大鼠的反应。在用雌二醇和孕酮进行卵巢类固醇替代后，在OVX大鼠中观察到多潘立酮的抑制作用：对照组OT为11.1±2.5，固定组OT为16.0±3.7 pmol/l。单独或联合用雌二醇和孕酮治疗OVX大鼠，均未改变OT应激反应。在任何实验组的对照或固定大鼠中，血管加压素的血浆水平均未显著改变。结果表明，高催乳素血症可能是泌乳大鼠中观察到的OT应激反应受损的一个致病因素。
