去窦弓神经大鼠下丘脑室旁核和视上核FOS和NADPH-d共存分布

NADPH-diaphorase activity and Fos expression in hypothalamic paraventricular nucleus and supraoptic nucleus in the rats following sinoaortic baroreceptor denervation

目的:探讨大鼠下丘脑室旁核和视上核神经元型一氧化氮合酶神经元是否参与中枢压力感受性反射通路。方法:应用Fos免疫组织化学结合还原型尼克酰胺腺嘌呤二核苷酸脱氢酶(NADPH-d)组织化学双重染色的方法,观察去窦弓神经术(SAD)后2hFos和NADPH-d在室旁核和视上核内的分布情况。结果:SAD大鼠室旁核小细胞部、大细胞部和视上核内有大量Fos表达,并与NADPH-d部分共存;NADPH-d/Fos双标记阳性神经元的比例分别为6.8%、72.1%和47.1%。在假手术组和正常对照组大鼠上述核团内偶见Fos阳性神经元,未观察到NADPH-d/Fos双标记神经元。结论:下丘脑室旁核和视上核内的神经元型一氧化氮合酶神经元可被SAD特异性激活,提示其参与了中枢压力感受性反射通路所介导的心血管活动的中枢调节。

Objective：To investigate whether neuronal nitric oxide synthase（nNOS） neurons in the hypothalamic paraventricular nucleus （PVN） and supraoptic nucleus （SON） were involved the central pathways of the arterial baroreflex in rats Methods： Immunocytochemical method for Fos combining with nicotinamide adenine dinucleotide phosphate diaphorase （NADPH-d） histochemical technique for nNOS was used to localize the Fos and NADPH expressions in the subdivisions of the PVN and SON following sinoaortic baroreceptor denervation （SAD）. Results：It was found that distinct number of Fos positive neurons coexisting with NADPH-d in the parvocellular subdivisions, magnocelluar subdivisions of the PVN and the whole SON. The percent of Fos/NADPH-d double-labeled neurons in the above regions was 6.8%, 72.1% and 47.1% respectively. Only few Fos positive neurons were observed at the above regions in the sham-operated and intact control rats, and no NADPH-d/Fos double-labeled neurons were detected. Conclusion：The nNOS neurons in the PVN and SON are activated by the SAD specifically, which highly indicates they may take part in the central cardiovascular regulation mediated by the arterial baroreflex.