面活性劑蛋白質 A 是肺部界面活性劑含量最豐富的一種界面活性劑蛋 白質，主要是由第二型肺泡細胞所分泌，含量約總界面活性劑蛋白質 的百分之五十，可降低肺泡的表面張力以利於氣體的交換是肺泡產生 功能的重要因子。臨床上，呼吸窘迫症候群是早產兒發生的主要症狀。該現象的發生乃因界面活性劑分泌不足之緣故。而現今臨床用藥之醣 質性皮質類固醇及外生性界面活性劑，均會造成早產兒日後腦部生長 及發育上不成熟及病變等副作用。本研究選用中草藥中，具安胎作用 之黃芩生藥主成分之一的黃芩苷 (Baicalin) 為測試的藥物，對肺癌細胞 株 H441 之界面活性劑蛋白質 A 進行時間性及劑量性分析的體外試驗。
由反轉錄 - 聚合脢連鎖反應及西方墨點法分析的結果顯示，界面活性 劑蛋白質 A 的表現量確實能隨著黃芩苷處理的時間及劑量的增加而增 加，在 150 nM 的黃芩苷處理 48 小時時，達最高的表現量。在互補去 氧核醣核酸減除法的分析結果可得知，黃芩苷是藉由增加細胞色素 C 氧化酶及類導換素促進蛋白的表現量來提高腺核苷三磷酸的形成，使 得蛋白質磷酸化作用旺盛，終至界面活性劑蛋白質 A 從第二型肺泡細 胞的分泌增加，或藉由調控轉錄機制來增加界面活性劑蛋白質 A 基因 的表現量。
黃芩 ? 對肺癌細胞株 H441 之界面活性劑蛋白質 A 基因表現的影響
Surfactant protein A (SP-A) is the most abundant surfactant protein component of pulm onary surfactant, constituting about 50% of the total surfactant protein. SP-A is a materi al secreted by the alveolar type II cell that reduces surface tension at the alveolar air-liq uid interface. It is an important role on the function of the alveolus.
Respiratory Distress Syndrome (RDS) is major cause of morbidity in preterm neonates, which results from a deficiency of pulmonary surfactant. Maternal glucocorticoid (ex: D examethasone) and exogenous surfactant (ex: Surrata and Exosurf) therapy decreased th e incidence of death and RDS, but the treatments glucocorticoid and exogenous surfacta nt have an adverse effect on the brain development of the premature infant.
Analysis of SP-A gene expression using RT-PCR, cDNA subtraction, Western Blotting and 2D in this study. The result of H441 cell culture assayed with RT-PCR and Western blot showed that the gene expression of SP-A was increased when treating with Baicali n (one of the major components of Scutellariae Radix) in time and dosage model. The m aximal gene expression of SP-A is exhibited at 150 nM baicalin treated for 48 hours wh en cDNA subtraction analysis performed. The result shown that treated with baicalin in creased copper-zinc superoxide dismutase and cytochrome C oxidase expression and tra nsducin-like enhancer of split 1, which resulted in the elevation of ATP level in the cell, the SP-A secretion thereby increased consistently.
Effects of Baicalin on the gene expression of surfactant protein A (SP-A) in lung
adenocarcinoma cell line H441
