The Effect of Anoxia and Reoxygenation on Synthesis of Nitric Oxide, ICAM-1 and VCAM of Umbilical Vein Endothelium

ABSTRACT

PURPOSE: The reperfusion flowing ischemia are associated with high systemic complication rates and severe local tissue injuries, which are primarily related to the reperfusion process. Anoxia or hypoxia and reoxygenation are principal components of ischemia and reperfusion (I/R) and in I/R injury model endothelial cell injury is known to be a initial event. The purpose of this study is to examine the changes of the levels of nitric oxide (NO), intercellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule (VCAM) of the cultured endothelial cells following anoxia and reoxygenation. METHODS: Experimental groups were divided into 4 groups control group, without any treatment; anoxia group (A-G), treatment with anoxic air (93% N2, 5% CO2, 2% H2) for 20 minutes; reoxygenation group (RO-G), treatment with 100% O2 for 90 minutes; superoxide dismutase (SOD) group, treatment with SOD just before reoxygenation. Endothelial cells were isolated from human umbilical vein and cultured in M-199 medium. Using microelectrode and ELISA we studied the time-course changes of the levels of NO, ICAM-1 and VCAM of 4 groups. RESULTS: The concentration of NO in A-G was lower than that of control group (P<0.05). NO concentration of RO-G at 30 minutes reached the highest level of 4809.01 444.69 nM/1 105 cells/ml (P<0.005) and after then decreased. The concentration of ICAM-1 in A-G was higher than that of control group (P<0.005). ICAM-1 concentration of RO-G at 15 minutes reached the highest level of 7.18 0.62 ng/1 105 cells/ml (P<0.005) and then decreased to the lowest level but after 75 minutes increased again. The concentration of VCAM in A-G was higher than control group (P<0.005). VCAM concentration of RO-G at 15 minutes reached the highest level of 5.50 0.55 ng/1 105 cells/ml (P<0.05) and then decreased to the lowest level at 45 minutes, but after 60 minutes the concentration increased again. SOD group showed a little change of NO, ICAM-1 and VCAM concentration comparing with both A-G and RO-G. CONCLUSION: This study showed that endothelial cell function of reoxygenation group decreased significantly compared with anoxia group. In anoxia and reoxygenation group, the levels of two adhesion molecules of ICAM-1 and VCAM increased faster than those of NO and the change of the level of ICAM-1 was more sensitive than that of VCAM. In reoxygenation group SOD treatment could inhibit the changes of the levels of NO, ICAM-1 and VCAM.