Impact of small-volume resuscitation using distinct solutions on tissue pathology and oxidative stress in rats with endotoxin shock

Abstract

Objective To investigate the effects of small-volume resuscitation using 7.5％ sodium chloride,hydroxyethyl starch 130/0.4 (WanwenTM) and hyperosmic sodium chloride on renal injury,superoxide dismutase (SOD) and malonaldehyde (MDA) in rats with endotoxin shock.Methods Thirty SD rats weighting 180 g-250 g were randomized into 5 groups (n=6):normal control (group N),endotoxin shock group (LPS,group E),7.5％ hyperosmic sodium chloride solution resuscitation group (LPS+HSS,group HSS),hydroxyehtyl starch solution 130/0.4 resuscitation group (LPS + HES,group HES),and hyperosmic sodium chloride with hydroxyethyl starch 40 solution resuscitation group (LPS + HSH,group HSH).Small-volume resuscitation was administrered after LPS injection except for group N.Heart rate and systolic pressure were recorded at different time points.The renal pathological examination was performed after 60 minutes,and the renal cortex MDA level and superoxide dismutase activity were measured.The ratio of dry/wet weight of kidney was also calculated.Results Rats with sepsis had a higher heart rate and lower systolic pressure followed by lower heart rate and increased arterial blood pressure after resuscitation.Pathological changes in terms of renal tubular necrosis,foot process fusion and basement membrane thickening occurred in group E and were ameliorated in resuscitation groups.In group E,SOD activity was reduced [ ( 125.27 ±32.28 ) U/ml vs ( 340.53 ±42.25 ) U/ml,P＜0.05 ] and MDA increased [ ( 1.08 ±0.15 ) μmol/L vs.(0.35±0.08) μmol/L,P＜0.05].A reduction in MDA content was found in group HES and HSS [ (0.64±0.18) μmol/L and (0.63±0.15) μmol/L vs(1.08±0.15) μmol/L,P＜0.05],and increased activity of SOD was shown after small- volume resuscitation [ (233.06± 75.60) U/ml and (210.21 ± 52.73) U/ml and (231.22 ±77.78 ) U/ml vs (125.27±32.28)U/ml,P＜0.05].Conclusion Oxidative lesion and pathological changes of renal injury are lessened in rats with endotoxin shock after small-volume resuscitation using distinct solutions. Key words: Endotoxemia; Cardiopulmonary resuscitation; Kidney failure; Malonaldehyde; Superoxide dismutase