一氧化氮通过视上核抑制大鼠射乳反射

Inhibition of rat's milk-ejecting reflex by ntric oxide through the supraoptic nucleus

为阐明中枢一氧化氮（NO）对射乳反射抑制性作用及其部位，我们采用孔内压测定方法，观察了视上核内注射NO供体L-精氨酸对授乳大鼠射乳反射的影响．结果发现，L-精氨酸对吸吮刺激所诱导的射乳具有明显的抑制性作用，该作用是剂量依赖性的、可被NO清除剂血红蛋白所拮抗。结果表明，中枢NO可能直接作用于视上核来实现其对反射性射乳的抑制。

To reveal the inhibitory effect of central nitric oxide (NO)on milk-ejecting reflex and the site related, by the measurement of intramammary pressure we observed the effect of intra-supraoptic nuclear injection of NO donor L-arginine on the reflex in lactating rats. The results showed that L-arginine significantly inhibited the ejection of milk induced by suckling stimuli, which was dose-dependent and was antagonized by intranuclear injection of NO scavenger,hemoglobin. Those results suggest that central NO possibly inhibits milk-ejection reflex through the supraoptic nucleus directly.