MARCKS相关多肽与地尔硫对大鼠气道黏液高分泌模型MUC5AC分泌的影响

Effect of MARCKS-related peptide and Diltiazem on Mucin 5AC secretion in a rat model of airway mucus hypersecretion

目的研究在大鼠气管内滴入MARCKS相关多肽(MANS)或/和地尔硫(DTZ)对气道黏蛋白5AC(MUC5AC)分泌的影响并探讨其可能的作用机制。方法通过雾化吸入丙烯醛建立大鼠气道黏液高分泌模型后随机分为4组,对照组气管内滴入生理盐水,三个实验组即MANS组、DTZ组和联用组在气管内分别滴入MANS、DTZ以及二者同时滴入,1 h后获取支气管肺泡灌洗液(BALF)及肺组织。用ELISA法对BALF中的MUC5AC进行定量;用免疫组化染色对气道杯状细胞中MUC5AC进行特异性染色,用灰度扫描和图像分析对杯状细胞内的MUC5AC进行半定量分析。结果BALF中MUC5AC的分泌量在MANS组和联用组均较对照组明显减少(P均<0.05),在DTZ组无明显变化(P>0.05);在联用组较MANS组亦明显减少(P<0.05)。气道杯状细胞内MUC5AC的量在MANS组和联用组均较对照组显著增多(P均<0.05);在单用DTZ组没有明显变化(P>0.05)。结论在丙烯醛诱导的大鼠气道黏液高分泌模型中,气管内滴入MANS可以减少气道黏液的分泌,单用DTZ气管内滴入不能减少气道黏液的分泌。但二者联合滴入时DTZ对MANS抑制气道黏液的分泌可能具有协同作用。

Objective To investigate the effects of MARCKS-related peptide（MANS） or/and Diltiazem （DTZ） on airway secretion of Mucin 5AC （MUCSAC）. Methods A rat model of airway mucus hypersecretion was established by aerosol inhalation of Acrolein for 6 hours per day for 12 days. Then 40 rats were randomly divided into four groups. Three experimental groups were administered via intratracheal instillation of MANS （10 mg/kg）, DTZ（0.2 mg/kg）, or combination of MANZ and DTZ, respectively. While the control group were implemented with normal saline. An hour later, bronchoalveolar lavage fluid（BALF） and lung specimens were sampled for detection of MUCSAC by ELISA and immunohistochemical stain, respectively. Results Compared with the control group, MUCSAC secrection in BALF significantly attenuated in the MANS group（ P 〈 0.05）, but decreased without significant difference in the DTZ group （ P 〉 0.05）. In the combination group, MUCSAC was significantly attenuated when compared with the MANS group and the control group respectively （both P 〈 0.05）. Compared with the control group, intracellular expression of MUCSAC in airway goblet cells in the MANS group and combination group significantly increased （both P 〈 0.05）, but did not increase significantly in the DTZ group（ P 〉 0.05 ）. Conclusions In the rat model of airway mucus hypersecretion induced by aerosol Acrolein inhalation, intratracheal instillation of MANS can attenuate mucus secretion. Intratracheal instillation of DTZ is likely to have synergic effects with MANS in decreasing mucus secretion, but have no significant effect alone. As a result of attenuation of extracellular mucus secretion MUCSAC is retained in goblet cells.