Luo Wei-Bo, Dong Li, Wang Yi-Ping
Shanghai Institute of Materia Medica, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200031, China.
Acta Pharmacol Sin. 2002 Oct;23(10):930-6.
To investigate the effect of magnesium lithospermate B (MLB) on hypoxia/ reoxygenation (H/R)-induced elevation of intracellular calcium concentration ([Ca2+]i) and nitric oxide (NO) release in endothelial cells.
The cultured human umbilical vein endothelial cells (ECV304) were exposed to hypoxia for 30 min under 95 % N2 and 5 % CO2, then reoxygenation for 30 min under air and 5 % CO2. Cell injury was evaluated by dye exclusion test, superoxide dismutase (SOD) assay, and molondialdehyde (MDA) assay. [Ca2+]i was determined by Fura 2-AM. NO content was examined by a NO assay kit. Endothelial nitric oxide synthase (eNOS) and inducible nitric oxide synthase (iNOS) mRNA expressions were measured by semi-quantitative RT-PCR.
Cell viability was decreased from (93.1+/-1.2) % in normoxia to (88+/-3) % in H/R (P < 0.01), and SOD activity was also decreased from (0.24+/-0.07) kNU/L to (0.18+/-0.03) kNU/L in H/R (P >0.05), but MDA production was increased from (1.12+/-0.06) mmol/L in normoxia to (3.78+/-0.03) mmol/L in H/R (P < 0.01) in ECV304 cultured under calcium conditions. MLB 2.5, 5, and 10 mg/L increased cell viability and SOD activity, and inhibited MDA formation in ECV304. H/R increased [Ca2+]i (F340/F380 from 1.65+/-0.16 to 1.89+/-0.28), NO release [from (7.5+/-1.3) micromol/L to (16+/-5) micromol/L], and eNOS mRNA expression, but decreased iNOS mRNA expression in ECV304 (P <0.05). However, it did not affect them under calcium-free conditions. MLB inhibited H/R-induced increases in [Ca2+]i and eNOS mRNA expression, stimulated NO release and iNOS mRNA expression (P <0.05).
MLB attenuates H/R-induced cell injury and increases NO release in ECV304. This increase of NO production is possibly associated with preventing cell injury induced by H/R in MLB-treated ECV304.
研究丹酚酸B镁（MLB）对缺氧/复氧（H/R）诱导的内皮细胞内钙浓度（[Ca2+]i）升高及一氧化氮（NO）释放的影响。
将培养的人脐静脉内皮细胞（ECV304）置于95%N2和5%CO2条件下缺氧30分钟，然后置于空气和5%CO2条件下复氧30分钟。通过染料排斥试验、超氧化物歧化酶（SOD）测定和丙二醛（MDA）测定评估细胞损伤。用Fura 2-AM测定[Ca2+]i。用NO检测试剂盒检测NO含量。通过半定量RT-PCR检测内皮型一氧化氮合酶（eNOS）和诱导型一氧化氮合酶（iNOS）mRNA表达。
在正常氧条件下细胞活力从（93.1±1.2）%降至H/R条件下的（88±3）%（P<0.01），在H/R条件下SOD活性也从（0.24±0.07）kNU/L降至（0.18±0.03）kNU/L（P>0.05），但在钙条件下培养的ECV304中，MDA产量从正常氧条件下的（1.12±0.06）mmol/L增加至H/R条件下的（3.78±0.03）mmol/L（P<0.01）。2.5、5和10mg/L的MLB可提高ECV304的细胞活力和SOD活性，并抑制MDA形成。H/R增加了ECV304中的[Ca2+]i（F340/F380从1.65±0.16升至1.89±0.28）、NO释放[从（7.5±1.3）μmol/L升至（16±5）μmol/L]以及eNOS mRNA表达，但降低了iNOS mRNA表达（P<0.05）。然而，在无钙条件下其对这些指标无影响。MLB抑制H/R诱导的[Ca2+]i和eNOS mRNA表达增加，刺激NO释放和iNOS mRNA表达（P<0.05）。
MLB减轻H/R诱导的ECV304细胞损伤并增加NO释放。这种NO生成的增加可能与预防MLB处理的ECV304中H/R诱导的细胞损伤有关。
