Protective Effect Of Magnesium On The Cultured Human Umbilical Vein Endothelial Cells Under Hypoxia-reoxygenation Injury

Objective To evaluate the effect of magnesium on the human umbilical vein endothelial cells (HUVECs) injured by hypoxia-reoxygenation and provide the theoretical evidence for clinical therapy.Methods Confluent cultures of HUVECs were exposed respectively. Experiments were divides into three groups, the first as bland group, the second as hypoxia-reoxygenation group and the third as magnesium group. Cells of the third group were incubated with culture including different concentration magnesium (2mmol/L, 4mmol/L, 8mmol/L, 11mmol/L, 16mmol/L), then treated by hypoxia-reoxygen. Microscopy was used to observe the features of cells. The contents of lactate dehydrogenase (LDH), malonaldehyde (MDA), nitric oxide (NO) and endothelin-1 (ET-1) in the medium were determined, while the glutathione (GSH) production in cell lysate of magnesium group were assessed. The correlation between different concentration magnesium and GSH, NO, ET-1 production were analyzed.Results (1)Structure of cells of hypoxia-reoxygenation group were damaged seriously,the mortality of cells of hypoxia-reoxygenation were high. Mortality of cells in magnesium group was significantly lower than that in hypoxia-reoxygenationgroup (p<0.05). (2)The contents of LDH and MDA in hypoxia-reoxygenation group were significantly higher than those in bland group.(P<0.001) ; The production of GSH in cell lysate and content of NO were higher in magnesium group than those in hypoxia-reoxygen group(P<0.05),while the contents of LDH and MDA were much lower in magnesium group than those in hypoxia-reoxgention group(P<0.05); The positive correlation between different concentration magnesium and GSH production was significant (r4=0.962, P<0.05). But the negative correlation between different . concentration magnesium and LDH production was significant (ri=-0.946,.P<0.05). (3)Content of NO in hypoxia-reoxygenation group was significantly lower than that in bland group (P<0.001), The content of ET-1 in hypoxia-reoxygenation group were significantly higher than that in bland group.(P<0.001) ;The positive correlation between different concentration magnesium and NO production was significant (r5=0.927,P<0.05;). But the negative correlation between different concentrationmagnesium and ET-1 production was significant (r6=-0.880,P<0.05).Conclusions (1) Hypoxia-reoxygenation can damage the structure of endothelial cells and increase the mortality of cells. Magnesium can protect the structure of endothelial cells and reduce the mortality of cells. (2)Magnesium has protective effect on vascular endothelial cell under hypoxia- reoxygenation injury. (3) Magnesium can increase the production of GSH in cell lysate and the content of NO in the liquid of cultured cells, while reduce the contents of LDH ,MDA and ET-1 in liquid of cultured cells. These data indicate that the protective role of magnesium may provide the theoretical evidence for improving endothelial dysfunction .