氨甲酰胆碱引起的促钠排泄反应和下丘脑室旁核胆碱乙酰转移酶免疫阳性反应变化

本研究选用清醒SD雄性大鼠,通过在体实验和免疫组化方法,观察大鼠侧脑室注射胆碱能激动剂氨甲酰胆碱(carbachol)0.5μg后,肾钠排泄量变化与室旁核胆碱乙酰转移酶(ChAT)表达的变化。结果显示侧脑室注射氨甲酰胆碱后40min,肾钠排泄量显著增加,室旁核的ChAT免疫反应阳性神经元数目明显增多(P<0.05),免疫染色强度明显增强(P<0.05);阿托品预处理后钠排泄量显著减少,下丘脑室旁核的ChAT免疫阳性反应(ChATIR)明显下降(P<0.05)。上述结果提示,侧脑室注射氨甲酰胆碱后,促钠排泄反应增强,下丘脑室旁核胆碱能神经元活性增强,阻断胆碱能受体后可下调氨甲酰胆碱诱导的上述变化。

CARBACHOL- INDUCED NATRIURESIS AND THE CHANGE OF CHOLINE ACETYLTRANSFERASE-IMMUNOREACTIVITY IN THE HYPOTHALAMUS PARAVENTRICULAR NUCLEUS

In the present study, we investigated the change of choline acetyltransferase (ChAT) expression in hypothalamus paraventricular neurons and natriuresis in kidney after intracerebroventricular (i.c.v.) injection of cholinergic agonist carbachol in conscious SD rats with immunohistochemistry and in vivo experiment. The results demonstrated that 40 minutes following i.c.v. injection of carbachol (0.5 μg), the natriuresis increased significantly and both the intensity of (ChAT)-immunoreactivity (ChAT-IR) and the number of ChAT-immunoreactive neurons were markedly increased in hypothalamus paraventricular nucleus. The enhancement was significantly reduced by i.c.v. injection of atropine. These results suggest that i.c.v. injection of cholinergic agonist carbachol can enhance natriuresis in kidney and the activity of cholinergic neurons in hypothalamus paraventricular nucleus. The blockade of acetylcholine receptor may down regulate the aforementioned activity induced by carbachol. both in hypothalamus paraventricular nucleus and kidney.