内毒素休克新生大鼠血清一氧化氮对心肌细胞第二信使的调节作用  

Modulatory effects of nitric oxide on cyclic adenosine monophosphate and cyclic guanosine 3,5-monophosphate in myocardial tissues of neonatal rats with endotoxic shock

作　　者：王虹[1] 吴玉斌[1] 李玉杰[1] 杜秀华[1] 

机构地区：[1]中国医科大学第二临床学院儿科,辽宁沈阳110004

出　　处：《中国危重病急救医学》2002年第5期285-287,共3页Chinese Critical Care Medicine

基　　金：辽宁省科委博士启动基金课题的部分内容〔 No.辽 (96) 10〕

摘　　要：目的 :观察新生大鼠内毒素休克时血清一氧化氮 (NO)与心肌环磷酸腺苷 (c AMP)、环磷酸鸟苷(c GMP)的关系 ,探讨 NO在地塞米松 (Dex)治疗新生儿感染性休克中对细胞第二信使的介导作用。方法 :健康7日龄 Wistar大鼠 117只 ,随机取 9只为实验前基础值组 ,余 10 8只按腹腔注射的药物不同 ,分成对照组 (生理盐水 )、休克组〔精制内毒素 (L PS) 5 mg/ kg〕及治疗组 (L PS 5 mg/ kg加 Dex 5 m g/ kg) ,每组 9只。各组于实验后2、4、6和 2 4小时分别断头取血测定血气及血清 NO变化 ,并留取心脏组织 ,用放射免疫法测定心肌 c AMP及c GMP浓度。结果 :1与对照组比较 ,休克组血清 NO于 2小时开始显著升高 (P<0 .0 1) ,2 4小时达到高峰 ,浓度约为 0时的 12倍 ;Dex组血清 NO于 4小时开始升高 (P<0 .0 5 ) ,2 4小时达到高峰 (P<0 .0 1) ,但升高程度低于休克组 (P<0 .0 1)。 2与对照组比较 ,休克组心肌 c AMP、c GMP2小时开始升高 (P均 <0 .0 5 ) ,随时间延长逐渐增高 ,于 2 4小时浓度最高 (P均 <0 .0 1) ;Dex组心肌 c AMP、c GMP于 2小时显著升高 ,显著高于休克组 (P均 <0 .0 1) ,为基础值的 2倍 (P均 <0 .0 1) ,此后逐渐下降 ,至 2 4小时接近对照组。 3休克组血气在 2 4小时出现显著代谢性酸中毒、呼吸性碱中毒伴低氧?Objective:To observe the protective effects of dexamethasone(Dex) on myocardial cells of neonatal rats with endotoxine shock through mediation of cyclic adenosine monophosphate(cAMP) and cyclic guanosine 3,5monophosphate(cGMP) by nitric oxide(NO).Methods:One hundred and seventeen sevendayold healthy newborn Wistar rats were randomly divided into 4 groups:①base value group;②control group,with intraperitoneal injection of 0 1 ml 0 9% sodium chloride;③endotoxin shock group 〔lipopolysaccharide (LPS) group〕,with single bolus injection of same amount of LPS 5 mg/kg to each rat;④treatment group(Dex group),given Dex 5 mg/kg immediately after LPS 5 mg/kg.At the designed time points(2,4,6 and 24 hours post injection),9 newborn rats were killed,central blood samples were collected for assaying NO,bloodgas,and myocardial tissue was also collected for determining cAMP and cGMP.The concentrations of myocardial cell cAMP and cGMP were measured with radioimmunoassay.Results:①The concentration of serum NO was significantlyincreased ( P <0 01) in LPS group from 2 hours to 24 hours,peaking at 24 hours,while in Dex group,the levels of serum NO were lower(all P <0 01)than that in LPS group at any time point.②The concentrations of myocardial cAMP and cGMP in LPS group rose significantly( P <0 05 and P <0 01,respectively) from 2 hours till 24 hours,while in Dex group,the highest concentrations of cAMP and cGMP were at 2 hours,and they were significantly higher than those in control group and LPS group (both P <0 01),and then they declined to the value of control group at 24 hours.③Metabolic acidosis with respiratory alkalosis was found in the rats with endotoxic shock.Conclusions:There is an imbalance between cAMP and cGMP in newborn rats with endotoxic shock,and NO is the mediator.Dex may partly protect the damage to myocardial cells by regulating the second messenger system in endotoxic shock of neonates.

关 键 词：地塞米松 内毒素性休克 一氧化氮 环磷酸腺苷 环磷酸鸟苷 大鼠 

分 类 号：R605.97[医药卫生—急诊医学]