Effect of mesenteric lymph obtained during shock on pump activity and oxygen free radical on erythrocyte membrane of rat

Abstract

To observe the effects of mesenteric lymph drainage and transfusion on pump activity and oxygen free radical of erythrocyte membrane of rats following hemorrhagic shock or normal, respectively. Twenty-four male Wistar rats were randomly divided into sham-shock group, shock group, shock mesenteric lymph drainage group (drainage group) and shock mesenteric lymph transfusion group (transfusion group) by randomization, with 6 rats in each group. Model of hemorrhagic shock was reproduced both in shock group and drainage group after anesthesia and operation, mesenteric lymph was drained 1 hour after shock in drainage group. Sham-shock group only received anesthesia and laparotomy, and the obtained mesenteric lymph was transfused in transfusion group. Blood was obtained from abdominal aorta, and red cell membrane suspension was prepared after 3 hours of shock or corresponding time, then the indices of erythrocyte membrane pump activity and oxygen free radical were determined. Compared with sham-shock group, the activity of Na(+)-K(+)-ATPase (μmol×mg(-1)×h(-1)), Ca(2+)-ATPase (μmol×mg(-1) ×h(-1) ) and superoxide dismutase (SOD) (NU/mg)of red cell membrane were decreased markedly (Na(+)-K(+)-ATPase: 0.039±0.011 vs. 0.068±0.010; Ca(2+)-ATPase: 0.035±0.016 vs. 0.087±0.015; SOD: 0.785±0.289 vs. 1.202±0.328, P<0.05 or P<0.01), and the content of malondialdehyde (MDA, nmol/mg) was increased markedly in shock group (1.914±0.225 vs. 0.913±0.138, P<0.01). Compared with shock group, the activity of Na(+)-K(+)-ATPase (0.056±0.009), Ca(2+)-ATPase (0.079±0.025) and SOD (1.220±0.380) of red cell membrane were increased in drainage group, and the level of MDA (1.214±0.127) was decreased markedly (P<0.05 or P<0.01). Compared with sham-shock group, the activity of Na(+)-K(+)-ATPase (0.050±0.013), Ca(2+)-ATPase (0.056±0.023) of red cell membrane in transfusion group were significantly lower (both P<0.05), the content of MDA (1.456±0.270) was significantly higher (P<0.01), respectively, the activity of SOD (0.862±0.288) showed a lowering trend, but there was no statistical significance (P>0.05). Mesenteric lymph return is a key factor in decreasing pump activity while aggravating free radical damage injury of erythrocyte membrane.