2026-11-092026-11-09https://scholars.csmu.edu.tw/handle/123456789/38541Sevoflurane is an inhalation anesthetic using for general anesthesia. The advantages of sevoflurane include a more rapid onset and recovery due to its lower solubility in blood and a relatively less irritation to the airway thus making it well suited as an induction drug for children. The minimum alveolar concentration (MAC) of sevoflurane is reported to be between 1.71% and 2.05%. The MAC for sevoflurane is somewhat higher in children. Typical values are 2.6% in children and 3.3% in neonates. Previous study showed that sevoflurane inhibits NADH/ubiquinone oxidoreductase activity, suggesting that complex I is a likely target. Other studies demonstrated that reactive oxygen species (ROS) exist in cardioprotection when preconditioned with sevoflurane. It also directly triggers the formation of peroxynitrite, inducing nitrolysation of sarcolemmal proteins. In contrast to small quantities of ROS required to initiate sevoflurane-induced preconditioning, large amounts of ROS play a major role in the pathophysiology of reperfusion injury. Sevoflurane also produces cardioprotection by attenuating the adverse effects of ROS burst upon reperfusion. Because of its cardioprotective effects, researches of sevoflurane focus mainly on heart or myocardium. Indeed, sevoflurane distributes to circulation and affects leukocytes within. In peripheral, polymorphonuclear neutrophils (PMN) are a major component of non-antigen-specific, cell-mediated immune system. They generate extremely high amounts of ROS to defeat pathogenic microorganisms. Current studies on neutrophils treated with sevoflurane have demonstrated that neutrophils lost their ability to cause cardiac dysfunction and inflammation as well as reduce superoxide production and adherence to the endothelium. Surprisingly, all these experiments carried out a neutrophil-stimulated or primed condition by using fMLP, PAF, or PMA. Without these activations, they couldn』t observe any benefits of sevoflurane on neutrophils or explain the virtue of anesthetic preconditioning (APC). Some reports even used hearts, neutrophils, or endothelia from different species to execute experiments. They couldn』t rule out interaction between species. To clarify the exact physical properties of PMN following sevoflurane treatment, we used whole blood from healthy volunteers to execute our experiments in our current NSC program (NSC 95-2320-B-040-014). The results have showed that sevoflurane significantly increased intracellular H2O2 and/or peroxide, superoxide, and nitric oxide in PMN within 1 h treatment. Intensification of intracellular glutathione (GSH) depletion in PMN was also demonstrated. These results were of our expectations and interest us to evaluate the following issues. (1) Effects of sevoflurane have been carried out in epithelium, endothelium, myocardium, platelets, and vascular smooth muscle cells, and many pharmacological properties were recorded therein. However, information in regard to the effects of sevoflurane on oxidative stress of these cells is scant. Thus, we would like to evaluate the oxidative status of other cells, especially those contact sevoflurane directly such as bronchial epithelial and endothelial cells, to clarify the ROS-promoting properties are general or cell-type specific. (2) Is the ROS-promoting character of sevoflurane resulting in these phenomena observed? What molecular mechanism and signal transduction pathway corresponds with the generation of ROS? (3) Does ROS generation and downstream signal transduction pathway result in the formation of proinflammatory mediators or expression of adhesion molecules? We are planning to solve these questions the following three years to solve each problem.七氟烷（Sevoflurane）是新一代的吸入性麻醉劑，用於成年及兒童病患之住院或門 診手術之全身性麻醉的誘發及維持，使用量為0.5～5.0%。它對呼吸道無刺激、麻醉效 力強、起效和甦醒迅速、對循環系統影響小，亦十分適用於心臟疾病患者。進行麻醉 時，大部分七氟烷以原型存在循環系統，它可以減緩缺血-再灌流組織之自由基累積造 成的損傷進而保護心臟。有趣的是：七氟烷會專一性地抑制粒線體電子傳遞鏈酵素 NADH/ubiquinone oxidoreductase 活性，增加超氧自由基生成量，但合併抗氧化劑處理， 反而抑制七氟烷引起之心肌保護效果。由此可知：七氟烷之保護機制與自由基生成量、 作用時間及心肌細胞與其他細胞間的相互作用有明顯的關聯性。然而，有關七氟烷對 血球影響的報導卻很少，雖然有研究指出：七氟烷會降低中性球與內皮細胞的附著力、 減緩發炎現象，但這些研究卻先使用一些細胞趨化劑誘發產生大量自由基或活化訊息 傳遞，再評估七氟烷之作用，而且這些實驗使用源自不同物種之心臟、細胞及中性球 共同培養，趨化物質的使用及不同物種間的效應是否能反應實際生理狀況值得商榷。 在95 年國科會計畫中，我們利用人類多形核白血球（PMN）來評估細胞經七氟烷 暴露之影響，目前結果顯示PMN 經1%或3%七氟烷處理30 分鐘，可增加細胞超氧 自由基、過氧化氫、一氧化氮及其他過氧化物並明顯消耗細胞抗氧化物質-穀胱甘.； 此外，利用單細胞電泳法(Comet assay)評估DNA 受傷害程度發現：隨七氟烷處理時間 增加，PMN 的DNA 受損情形亦愈趨明顯。這是首次發現七氟烷引起PMN 產生自由基 及DNA 損傷，因此，我們有興趣在未來的研究計畫中繼續探討下列問題： 1. 七氟烷在PMN 誘發之自由基生成現象是否也存在其他細胞？在第一年的計畫中， 我們將嘗試使用人類支氣管上皮細胞、人類臍帶內皮細胞及小鼠內皮細胞（這些細胞 在麻醉進行時，會直接與七氟烷接觸）來評估細胞內超氧自由基、過氧化氫、一氧化 氮、其他過氧化物及細胞內穀胱甘.的含量是否如PMN 一樣會受七氟烷影響。 2. 自由基常扮演次級傳訊者(second messengers)的角色，引發細胞一連串的訊息傳遞途 徑。因此，第二年計畫中我們想探討七氟烷促使ROS 量增加之分子機轉（例如：NF豈B, I豈B, IKK, MEKK, MAPK, PI3K 等蛋白質表現及訊息傳遞途徑，是否受七氟烷影響）。 3. 因發炎反應牽涉各種血球細胞之分泌物與血管內皮細胞貼附因子表現等複雜作用， 所以第三年計畫中，我們想探討經七氟烷處理後，血管內皮細胞發炎性物質（例如： IL-6 及TNF脈）及細胞貼附因子（例如：E-selectin, VCAM-1, and ICAM-1）等表現 情況。期望透過計畫執行，釐清七氟烷對血管內皮細胞之影響及作用機制，為基礎研 究與臨床應用提供更有力之參考依據。七氟烷自由基氧化傷害粒線體功能細胞凋亡sevofluraneepitheliumendotheliumROSinflammationadhesion moleculesProject