目的:应用离体淋巴管灌流技术,观察一氧化氮(NO)在失血性休克(HS)大鼠离体淋巴管对P物质(SP)反应性双相变化中的作用.方法:Wistar雄性大鼠随机分为对照组(仅手术)和休克组(复制HS模型后分为shock 0.5 h、shock 2 h组).在相应时点分离胸导管,制备淋巴管条,3 cmH2O跨壁压下行离体灌流,应用一氧化氮合酶(NOS)工具药分别孵育shock 0.5 h和shock 2 h的淋巴管.分别给予从低到高浓度的SP,测量淋巴管收缩末期口径、舒张末期口径、收缩频率(CF)和被动管径,计算收缩幅度(CA)、泵流分数(FPF)和紧张指数(TI),以给予SP前后淋巴管的CF、TI、CA和FPF的差值ΔCF、ΔTI、ΔCA和ΔFPF评价淋巴管对SP的反应性.结果:NO供体L-Arg可显著降低shock 0.5 h淋巴管对多个SP浓度点的ΔCF、ΔTI与ΔFPF;可溶性鸟苷酸环化酶抑制剂ODQ可显著抑制L-Arg的作用,在某些SP浓度点上,使ΔCF、ΔTI和ΔFPF显著高于shock 0.5 h+L-Arg组,ΔCF和ΔFPF高于对照组水平.NOS抑制剂L-NAME可提高shock 2 h淋巴管对多个SP浓度点的ΔCF、ΔTI与ΔFPF,且高于对照组水平;shock 2 h淋巴管与L-NAME和磷酸二酯酶抑制剂氨茶碱(AP)同时孵育后,在SP为1×10-8 mol/L和3×10-8 mol/L时,AP显著抑制了L-NAME的作用,使ΔCF、ΔTI与ΔFPF明显降低.结论:NO参与了休克淋巴管反应性的双相调节,其机制可能是通过环鸟苷酸实现的.%AIM:To observe the role of nitric oxide ( NO ) in the reactivity of isolated lymphatics to substance P ( SP), which presents a biphasic change, in the hemorrhagic shock ( HS ) rats with the technique of lymphatic perfusion in vitro. METHODS:Male Wistar rats were randomly divided into control group ( surgical procedure only) and shock group ( the rats were further divided into shock 0. 5 h and shock 2 h groups after the HS model was established ). A segment of lymphatics was pressed and perfused in vitro at transmural pressure of 3 cmH2 O after thoracic ducts were separated from the rats at the corresponding time points in each group. The lymphatics of shock 0. 5 h and shock 2 h were incubated with different drugs for changing the activity of No and nitric oxide synthase ( NOS ), respectively. The end - systolic diameter, end - diastolic diameter, contraction frequency ( CF ) and passive diameter of isolated lymphatics were measured, while the contraction amplitude ( CA ), tonic index ( TI) and fractional pump flow ( FPF ) were calculated after stimulated with gradient SP. Different values between pre - and post - administration of SP in CF, CA, TI and FPF were calculated and expressed as ACF, ATI, ACA and AFPF for further assessing the reactivity of lymphatics. RESULTS: NO donor L - Arg reduced ACF, ATI and AFPF of 0. 5 h - shocked lymphatics treated with different concentrations of SP. The effect of L -Arg was obviously suppressed by a soluble guanylate cyclase inhibitor ODQ. ACF, ATI and AFPF increased strikingly compared with shock 0. 5 h + L - Arg group in the presence of SP at certain concentration, and ACF and AFPF increased remarkably compared with control group.NOS inhibitor L - NAME elevated ACF,ATI and AFPF of 2 h - shocked lym-phatics treated with different concentrations of SP and the manifestation of lymphatics exceeded the values of control levels. In the experiment of 2 h - shocked lymphatics treated with L - NAME + phosphodiesterase inhibitor aminophylline ( AP ), the effect of L - NAME was suppressed significantly, which manifested by the decrease in ACF, ATI and AFPF as compared with the values of shock 2 h + L - NAME group in the presence of SP at the concentrations of 1×10-8 mol/L and 3× 10-8 mol/L. CONCLUSION: These data indicate that NO involves in the biphasic modulation of shocked lymphatics and the effect might be involved in the action of cyclic guanosine monophosphate.
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