本研究观察射干麻黄汤(SGMHD)对大鼠冷哮喘的治疗作用,并探讨其作用机制。将72只健康雄性无特异性病原体(SPF)级SD大鼠随机分为空白组,一个模型组,阳性对照组(地塞米松,0.4mg·kg~(-1)),和低,medium-,和高剂量SGMHD组(3.2、6.4和12.8g·kg〜(-1))。空白组接受生理盐水,其他组均通过腹腔注射卵清蛋白(OVA)溶液致敏。随后,将大鼠置于可调节至0-2℃的冷室中,超声雾化OVA溶液诱导大鼠冷哮喘。经过三周的治疗,观察大鼠的一般行为。苏木素-伊红(HE)染色评价肺组织病理变化,高碘酸希夫(PAS)染色评估粘蛋白变化,并进行Masson染色以检查胶原沉积。采用酶联免疫吸附试验(ELISA)检测血清和支气管肺泡灌洗液(BALF)中炎性因子白细胞介素-4(IL-4)和血管内皮生长因子(VEGF)的水平。实时定量聚合酶链反应(RT-PCR)用于评估瞬时受体电位香草素亚家族成员1(TRPV1)的mRNA表达水平,核呼吸因子1(NRF-1),和肺组织中的线粒体转录因子A(mtTFA)。Westernblot用于检测肺组织中TRPV1、NRF-1和mtTFA的蛋白表达水平。与空白组相比,模型组表现出快速呼吸的迹象,排便频率增加,大便松弛,蓬乱沉闷的皮毛.病理成果显示肺组织有显著的炎性细胞浸润,支气管管腔变窄,粘蛋白分泌增加,模型组胶原沉积增强。此外,血清和BALF中IL-4和VEGF水平显著升高,肺组织中TRPV1、NRF-1和mtTFA的mRNA和蛋白表达水平显著升高。与模型组相比,SGMHD改善大鼠的行为,减轻肺组织的病理变化,粘蛋白生产,和胶原蛋白沉积,显著降低血清和BALF中IL-4和VEGF的水平,并降低肺组织中TRPV1、NRF-1和mtTFA的mRNA表达水平,中剂量SGMHD组显示出最显著的效果。此外,肺组织中TRPV1、NRF-1和mtTFA的蛋白表达水平也降低,中剂量SGMHD组表现出最显著的效果。总之,这项研究表明,SGMHD可以减轻寒冷性哮喘大鼠的气道炎症和抑制气道重塑。这些效应可能与TRPV1/NRF-1/mtTFA信号通路的调节有关。
This study investigated the therapeutic effect of Shegan Mahuang Decoction(SGMHD) on cold-induced asthma in rats and explored its underlying mechanism. Seventy-two healthy male SD rats of specific pathogen free(SPF) grade were randomly divided into a blank group, a model group, a positive control group(dexamethasone, 0.4 mg·kg~(-1)), and low-, medium-, and high-dose SGMHD groups(3.2, 6.4, and 12.8 g·kg~(-1)). The blank group received saline, while the other groups were sensitized by intraperitoneal injection of ovalbumin(OVA) solution. Subsequently, the rats were placed in a cold chamber adjustable to 0-2 ℃, and OVA solution was ultrasonically nebulized to induce cold-induced asthma in rats. After three weeks of treatment, the general behaviors of rats were observed. Hematoxylin-eosin(HE) staining was used to evaluate pathological changes in lung tissues, periodic acid-Schiff(PAS) staining assessed mucin changes, and Masson staining was performed to examine collagen deposition. Enzyme-linked immunosorbent assay(ELISA) was used to measure the levels of the inflammatory factors interleukin-4(IL-4) and vascular endothelial growth factor(VEGF) in serum and bronchoalveolar lavage fluid(BALF). Real-time quantitative polymerase chain reaction(RT-PCR) was employed to assess the mRNA expression levels of transient receptor potential vanilloid subfamily member 1(TRPV1), nuclear respiratory factor 1(NRF-1), and mitochondrial transcription factor A(mtTFA) in lung tissues. Western blot was used to measure the protein expression levels of TRPV1, NRF-1, and mtTFA in lung tissues. Compared with the blank group, the model group exhibited signs of rapid respiration, increased frequency of defecation with looser stools, and disheveled and dull fur. Pathological results showed significant infiltration of inflammatory cells in lung tissues, narrowing of bronchial lumens, increased mucin secretion, and enhanced collagen deposition in the model group. Additionally, the levels of IL-4 and VEGF in serum and BALF were significantly elevated, and the mRNA and protein expression levels of TRPV1, NRF-1, and mtTFA in lung tissues were significantly increased. Compared with the model group, SGMHD improved the behaviors of rats, alleviated pathological changes in lung tissues, mucin production, and collagen deposition, significantly decreased the levels of IL-4 and VEGF in serum and BALF, and reduced the mRNA expression levels of TRPV1, NRF-1, and mtTFA in lung tissues, with the medium-dose SGMHD group showing the most significant effect. Moreover, the protein expression levels of TRPV1, NRF-1, and mtTFA in lung tissues were also reduced, with the medium-dose SGMHD group exhibiting the most significant effect. In conclusion, this study demonstrates that SGMHD can alleviate airway inflammation and inhibit airway remodeling in cold-induced asthma rats. These effects may be associated with the modulation of the TRPV1/NRF-1/mtTFA signaling pathway.