去甲肾上腺素与脂质过氧化关系的研究

本实验观察到,一定浓度的去甲肾上腺素可显著抑制自由基发生系统引起的离体大鼠肝细胞及磷脂脂质体的过氧化,减轻脂质过氧化所致肝细胞LDH漏出及细胞内 Ca~(2+)积聚。10~(-4)mol/L去甲肾上腺素明显抑制花生四烯酸的过氧化。

THE IN VITRO EFFECTS OF NOREPINEPHRINE ON LIPID PEROXIDATION

Incubation of rat hepatocytes with norepinephrine (NE) in vitro showed that 10~(-6) -10~(-5) mol/L NE inhibited the increase of cellular malondialdehyde (MDA) content induced by free radical gene- rating system (FRGS-Fe~(2+) and ascorbic acid). The inhibition rate of 10~(-5) mol/L NE was 43.3% (P< 0.01). NE also reduced the FRGS-induced cellular damage, inhibiting both the leakage of cytoplasmic enzyme lactic dehydrogenase (LDH) and the increase of intracellular Ca~(2+) content. On biomembrane- phospholipid liposome, a model of cellular membrane, 10~(-2)-10~(-4) mol/L NE also showed inhibition of lipidperoxidation induced by FRGS. NE had a biphasic effect on the FRGS-induced peroxidation of arachidonic acid. 10~(-4) mol/L NE inhibited arachidonic acid peroxidation induced by FRGS, but 10~(-6) mol/L and 10~(-8) mol/L NE aggravated it. These results suggest that NE may affect the cellular lipi- dperoxidation through affecting the unsaturated fatty acid in the phospholipid molecule on the cell membrane.