摘要
目的 :探讨三磷酸腺苷 (ATP)敏感钾通道开放剂拉马克啉 (Lev)对缺氧条件下培养的肺动脉内皮(PAEC)及平滑肌细胞 (PASMC)的影响及其可能的作用机制。方法 :分析Lev对缺氧条件下培养的PAEC及PASMC的[Ca2 +]i、上清液中NO-2 及ET - 1水平、细胞内PKCα、eNOS、iNOS及PDGF -B的mRNA和蛋白质水平及PASMC增殖和凋亡的影响及其作用的细胞内机制。结果 :①Lev可降低缺氧时PASMC及PAEC上清液中ET - 1及细胞内PKCα、iNOS及PDGF -B的mRNA和蛋白质水平 ,可降低PASMC[Ca2 +]i,抑制PASMC增殖 ,促其凋亡 (P均 <0 0 5 ) ,而对PAEC [Ca2 +]i 及PASMC、PAEC上清液中NO-2 水平及细胞内eNOS的mRNA和蛋白质水平无明显影响 (P均 >0 0 5 )。②Lev下调缺氧时PASMC及PAEC上清液中ET - 1水平及PASMC增殖的机制涉及抑制缺氧时PKCα 信号通道的功能活性。结论 :Lev可减轻缺氧对PAEC及PASMC的某些不利影响 ,其作用的部分机制涉及下调缺氧时PAEC及PASMC内PKCα 信号通道的功能活性和降低PASMC的 [Ca2 +]i,而与eNOS -NO信号通道无关。
AIM: To explore the effects of levcromakalim(Lev) on pulmonary arterial endothelial cells (PAEC) and smooth muscle cells (PASMC) exposed to hypoxia and the mechanisms involved. METHODS: The effects of Lev on i, and expression of PKC α, eNOS, iNOS and PDGF-B mRNA and protein levels were observed. The nitrite (NO- 2) and entothelin-1(ET-1) concentrations in supernatant in cultured PAEC and PASMC were measured. The proliferation and apoptosis of PASMC was also detected. RESULTS: When PASMC were exposed to hypoxia, Lev reduced concentration of ET-1 in cultured cell supernatant, lowed the expression of PKC α, iNOS and PDGF-B both at mRNA and protein levels, decreased i concentration, increased proliferation and promoted the apoptosis in PASMC. However, in the presence of Lev, the i concentration was not changed in the hypoxic PAEC. The NO- 2 concentration in cultured cell supernant and expression of eNOS at mRNA and protein levels in hypoxic PASMC and PAEC were also unchanged. The downregulated ET-1 activity in PASMC and PAEC and proliferation in PASMC involved in the inhibition of PKC α signaling pathway. CONCLUSIONS: Lev reduce some disadvatage effect of hypoxia on PASMC and PAEC. The mechanism of Lev action may partly involve in the downregulation of PKC α signaling functions.
出处
《中国病理生理杂志》
CAS
CSCD
北大核心
2003年第4期481-486,共6页
Chinese Journal of Pathophysiology
基金
国家自然科学基金资助项目 (No .39970 332 )