低剂量氢化可的松对脓毒性休克早期心血管系统保护作用

Low-dose hydrocortisone protects cardiovascular system in early septic shock

目的研究低剂量氢化可的松对脓毒性休克早期心肌肌钙蛋白Ⅰ(cTnⅠ)及前列环素2(PGI2)的影响。方法用脂多糖(LPS)股静脉注射建立脓毒性休克早期模型。健康雄性SD大鼠24只,随机分为正常对照组(n=8),脓毒性休克组(n=8),低剂量氢化可的松组(n=8)。正常对照组注射等量的生理盐水代替LPS;其余各组均通过右股静脉注射LPS20mg/kg,低剂量氢化可的松组在模型建立成功后,予以氢化可的松5mg/kg股静脉注射;以休克后6h为实验终点,留取标本。通过Elisa法检测血浆中PGI2表达水平;采用免疫组化染色(IHC)检测大鼠cTnⅠ表达;HE染色观察大鼠心肌组织的病理变化。结果大鼠血浆中的PGI2水平,与正常对照组比,脓毒性休克组显著上升(P<0.05):给予低剂量氢化可的松干预后,与脓毒性休克组比,低剂量氢化可的松组的PGI2水平明显下降(P<0.05)。IHC染色cTnI表达:正常对照组cTnI表达水平最高,与正常对照组相比脓毒性休克组cTnI的表达水平明显下降(P<0.05),低剂量氢化可的松组与脓毒性休克组相比cTnI表达水平明显上升(P<0.05);HE染色:正常对照组无明显改变;脓毒性休克组出现明显的炎性浸润及细胞水肿,细胞轮廓不清;低剂量氢化可的松组细胞尚规整,无明显细胞肿胀。结论在脓毒性休克早期给予低剂量氢化可的松干预,对心血管系统具有保护作用,可能与抑制心肌损伤和心肌微循环损伤有关。

Objective To study the effect of low-dose hydrocortisone on cardiac troponinⅠ(cTnⅠ)and prostacyclin 2(PGI2)in early septic shock.Methods Early model of septic shock was established by intravenous injection of lipopolysaccharide(LPS).24 healthy male SD rats were randomly divided into normal control group(n=8),septic shock group(n=8),and low-dose hydrocortisone group(n=8).The normal control group was injected with the same amount of normal saline instead of LPS;the other groups were injected with LPS 20 mg/kg through the right femoral vein;after the model was established in the low-dose hydrocortisone group,hydrocortisone 5mg/kg was injected intravenously.after shock 6h as the end point of the experiment.PGI2 in rat plasma by ELISA,the expression of cTnⅠin rats by immunohistochemical staining(IHC);the pathological changes of rat myocardial tissue were observed by HE.Results The level of PGI2 in the plasma of rats was significantly increased in the septic shock group compared with the normal control group(P<0.05).After the low-dose hydrocortisone intervention,the PGI2 level in the low-dose hydrocortisone group was significantly decreased compared with septic shock group(P<0.05).IHC staining showed that the expression level of cTnI was the highest in the normal control group,and the expression level of cTnI was significantly decreased in the septic shock group compared with the normal control group(P<0.05),the expression level of cTnI was significantly increased in the low-dose hydrocortisone group compared with the septic shock group(P<0.05).HE staining showed that was no significant change in the normal control group;the septic shock group showed obvious inflammatory infiltration and cell edema,and the cell outline was unclear;the low-dose hydrocortisone group was still regular,and there was no obvious cell swell.Conclusions Low-dose hydrocortisone intervention in early septic shock has a protective effect on the cardiovascular system,which may be related to the inhibition of myocardial injury and myocardial microcirculation injury.