Johnson J H
Neuroendocrinology. 1982;35(3):169-72. doi: 10.1159/000123376.
Blood samples were collected via jugular catheters from ovariectomized rats at 10-min intervals for 1 h before and 2 h after microinjection of 0.5 microliter of either saline vehicle or morphine sulfate (10 micrograms) into the dorsal raphe nucleus (DRN) or adjacent periaqueductal gray by means of chronically-implanted guide cannulae. Prolactin was measured by radioimmunoassay, and mean preinjection and mean postinjection values were compared for each rat (t test) as well as for each treatment group (paired t test). Neither saline in DRN nor morphine in the surrounding periaqueductal gray significantly altered circulating prolactin. A significant rise in prolactin was observed following injection of morphine into DRN. This effect of morphine was prevented by pretreatment of the animals with the narcotic antagonist naltrexone (10 mg/kg i.v.), indicating the involvement of opiate receptors. These results indicate that DRN is one site at which systemically-administered morphine might act, and suggest the possibility of participation of this mechanism in modulation of prolactin release by endogenous opioids.
通过颈静脉导管从去卵巢大鼠采集血样，在通过长期植入的引导套管向背缝核（DRN）或相邻的导水管周围灰质微量注射0.5微升生理盐水或硫酸吗啡（10微克）之前1小时和之后2小时，每隔10分钟采集一次。通过放射免疫测定法测量催乳素，并对每只大鼠（t检验）以及每个治疗组（配对t检验）的注射前平均值和注射后平均值进行比较。DRN中的生理盐水和导水管周围灰质中的吗啡均未显著改变循环催乳素水平。向DRN注射吗啡后观察到催乳素显著升高。用麻醉拮抗剂纳曲酮（10mg/kg静脉注射）预处理动物可防止吗啡的这种作用，表明阿片受体参与其中。这些结果表明DRN是全身给药吗啡可能作用的部位之一，并提示该机制可能参与内源性阿片类物质对催乳素释放的调节。
