摘要
小量过氧化氢（Ｈ＿２Ｏ＿２）预处理，能诱导牛肺动脉内皮细胞（ＢＰＡＥＣｓ）中热休克蛋白７０（ＨＳＰ７０）及ＨＳＰ７０ｍＲＮＡ增多，同时使ＢＰＡＥＣｓ获得了对大量Ｈ＿２Ｏ＿２损伤的耐受性，表现为大量Ｈ＿２Ｏ＿２所致乳酸脱氢酶释放和硫代巴比妥酸反应物含量增加及过氧化氢酶、超氧化物歧化酶活性降低等变化减轻。用放线菌酮和放线菌素Ｄ分别抑制ＨＳＰ７０和ＨＳＰ７０ｍＲＮＡ的增多后，此种耐受性消失。说明小量Ｈ＿２Ｏ＿２预处理使ＢＰＡＥＣｓ对大量Ｈ＿２Ｏ＿２损伤作用产生耐受性与细胞内ＨＳＰ７０合成（包括转录和翻译两个水平）增加及抗氧自由基能力增强有关。
he tolerance of bovine pulmonary artery endothelial cells(BPAECs)to lethal dose of hydro-gen peroxide(H_2O_2)induced by pretreatment with mild dose of H_2O_2 was observed in vitro.Itwas found that BPAECs pretreated with H_2O_2(0.25mmol/L.30min)prior to exposure to H_2O_2(1mmol/L.45min)had significant decrease in H_2O_2-mediated increment of release of LDH andproduction of TBARS.and had a obvious alleviation in H_2O_2-induced decrease in activities of cata-lase and superoxide dismutase.SDS-PAGE discoverd rapid synthesis of HSPs induced by milddose of H_2O_2(0.25mmol/L).Western analysis indicated that after exposed to 0.2 5mmol/LH_2O_2.there is increase of HSP70.Northern analysis revealed that BPAECs.following pretreat-ment with H_2O_2(0.25mmol/Lfor 20.30min).contain a time-dependent increased level of HSP70mRNA.Further study showed that Cycloheximide.a protein synthesis inhibitor and Acti-nomycin D.a mRNA transcription inhibitor blocked the expression of HSP70 and HSP70 mRNArespectively.Both agents prevented the cytoprotective effect of 0.25mmol/LH_2O_2pretreatmentagainst H_2O_2-mediated BPAECs injury.We conclude that mild dose of H_2O_2 pretreatment couldinduce the tolerance of BPAECs to lethal dose of H_2O_2 and HSP70 gene selectively transcribedand translated after mild dose of H_2O_2 is involved in enhancement of cellular antioxidant mecha-nism and is protecting BPAECs against H_2O_2-induced injury.
出处
《基础医学与临床》
CSCD
1996年第1期39-43,共5页
Basic and Clinical Medicine
基金
国家自然科学基金
湖南省自然科学基金
