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腹膜淋巴孔与淋巴转归NO-cGMP-Ca~(2+)信号转导途径研究

李燕园, 李继承

浙江大学细胞生物学研究所.浙江，杭州 310031

摘要

为研究一氧化氮(nitric oxide, NO)调节大鼠腹膜淋巴孔和淋巴吸收的细胞内信号转导机制。在体外培养的间皮细胞上，利用cGMP检测试剂盒和激光共聚焦扫描显微镜，研究NO对间皮细胞内cGMP和游离[Ca~(2+)]_(i)的影响；并利用动物实验研究NO-cGMP-Ca~(2+)通路，对大鼠腹膜淋巴孔和淋巴吸收的影响。结果发现：（1）与对照组相比，NO供体Sper/NO（spermine/nitric oxide complex）可以剂量依赖性地升高间皮细胞内cGMP的浓度（P<0.01）。此作用可被可溶性鸟苷酸环化酶（soluble guanylyl cyclase, sGC）特异性抑制剂1H-[1,2,4]噁二唑[4,3-a]喹喔啉-1-one酮（1H-[1,2,4] oxadiazolo [4,3-a] quinoxalin-1-one, ODQ）阻断（P<0.05，P<0.01）。 Sper/NO可使间皮细胞内游离[Ca~(2+)]_(i) 相对水平降低(P<0.05)，但此效应可被ODQ阻断；L-型电压依赖性钙通道阻滞剂nifedipine，可使细胞内的游离[Ca~(2+)]_(i)在短时间内迅速明显下降(P<0.05)，达平衡后再加入的Sper/NO并不能引起细胞内Ca~(2+)浓度的进一步改变(P>0.05)。（2）NO可以剂量依赖性地提高大鼠膈组织淋巴孔最大分布面积(P<0.01) 和对示踪剂的吸收量(P<0.05)，ODQ可明显抑制NO引起的淋巴孔和淋巴吸收的改变(P<0.01)。该结果首次发现nifedipine能显著增加淋巴孔最大分布面积(P<0.01)及膈组织对台盼蓝的吸收量(P<0.05)，而且nifedipine预处理后Sper/NO并不能使淋巴孔的淋巴吸收进一步升高 (P>0.05)。结果提示，NO可以通过降低cGMP水平降低大鼠腹膜间皮细胞内游离[Ca~(2+)]_(i)，且此过程和L-型电压依赖性钙通道有关；NO可通过NO-cGMP-[Ca~(2+)]_(i)通路，促进淋巴孔的开放和吸收。

关键词： 淋巴孔; 信号转导; 间皮细胞; 一氧化氮; 大鼠

Effects of nitric oxide n peritoneal lymphatic stomata and lymph drainage via NO-cGMP-Ca~(2+) pathway

Li Yanyuan, Li Jicheng

Department of Lymphology, Institute of Cell Biology, Zhejiang University.Hangzhou 310031,Zhejiang

Abstract

To study the cell signal mechanism of nitric oxide (NO) on the peritoneal lymphatic stomata and lymph drainage in the rat, cGMP content were measured by a commercially available radioimmunoassay kit, and the [Ca~(2+)]_(i) were observed by a confocal laser scanning microscope in the cultured peritoneal mesothelial cell. Animal experiment was practiced to study the effect of NO-cGMP-Ca~(2+) pathway on the lymphatic stomata and lymph absorption. The results showed that (1) Sper/NO increased cGMP of the rat peritoneal mesothelial cell (RPMC) in a dose-dependent manner (P<0.01) compared to the control group. This effect was blocked by 1H-[1,2,4] oxadiazolo [4,3-a] quinoxalin-1-one (ODQ) (P<0.05), a specific inhibitor of soluble guanylyl cyclase (sGC). The level of [Ca~(2+)]_(i) in single RPMC decreased by adding of Sper/NO (P<0.05). Pretreatment with ODQ for 10 min blocked the Sper/NO-induced decrease [Ca~(2+)]_(i). L-typed calcium channel blocker nifedipine induced an immediate and marked decrease in [Ca~(2+)]_(i) (P<0.05). After [Ca~(2+)]_(i) reached a balance again, adding Sper/NO could not change [Ca~(2+)]_(i) (P>0.05). (2) Sper/NO increased the area of the stomata (P<0.01) and the quantity of the tracer in a dose-dependent manner (P<0.05) compared to the control group. Pretreatment with ODQ significantly inhibited Sper/NO-induced change of lymphatic stomata and lymph drainage (P<0.01). Nifedipine increased the opening area of the lymphatic stomata (P<0.01) and the concentration of absorbed trypan blue of the diaphragm (P<0.05). Sper/NO could not make a further change in the samples pretreated by nifedipine (P>0.05). The results indicate that NO can decrease [Ca~(2+)]_(i) in the RPMC through the NO-cGMP pathway. This procession is related with the L- type voltage-gated Ca~(2+) channel. NO enlarges the opening area of the lymphatic stomata and enhances the lymph drainage of tracer by NO-cGMP-[Ca~(2+)]_(i) pathway.

Key words: Lymphatic stomata;Signal transduction;Mesothelial cell;Nitric oxide;Rat

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引用本文：

李燕园, 李继承. 腹膜淋巴孔与淋巴转归NO-cGMP-Ca~(2+)信号转导途径研究[J]. 生理学报 2005; 57 (1): .

Li Yanyuan, Li Jicheng. Effects of nitric oxide n peritoneal lymphatic stomata and lymph drainage via NO-cGMP-Ca~(2+) pathway. Acta Physiol Sin 2005; 57 (1): (in Chinese with English abstract).