Effect of magnesium lithospermate B on calcium and nitric oxide in endothelial cells upon hypoxia/reoxygenation

Wei Bo Luo, Li Dong, Yi Ping Wang

Research output: Contribution to journalArticlepeer-review

21 Scopus citations

Abstract

AIM: 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. METHODS: 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. RESULTS: 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) μmol/L to (16±5) μmol/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). CONCLUSION: 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.

Original languageEnglish (US)
Pages (from-to)930-936
Number of pages7
JournalActa Pharmacologica Sinica
Volume23
Issue number10
StatePublished - Oct 1 2002
Externally publishedYes

Keywords

  • Anoxia
  • Calcium
  • Endothelium
  • Magnesium lithospermate B
  • Nitric oxide

ASJC Scopus subject areas

  • Pharmacology
  • Pharmacology (medical)

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