摘要
目的:探讨神经一氧化氮合酶(nNOS)与胎鼠缺血缺氧性脑损伤的关系及左旋硝基精氨酸(L-NNA)的保护作用。方法:建立胎鼠宫内窘迫模型。分为对照组、急性缺血组、治疗组(于缺血前1.5h孕鼠腹腔内注射L-NNA4mg/kg)。以比色法测定脑组织匀浆的NO值;RT-PCR检测nNOSmRNA的表达量;以TTC染色计算脑组织的相对缺血面积,并行定量分析。结果:①治疗组缺血5、15min的脑组织匀浆NO值明显低于急性缺血组(P<0.05),但仍高于对照组。缺血30min时,急性缺血组与治疗组差异无显著性意义,但均高于对照组(P<0.05)。②缺血5min、15min、30min的胎鼠脑组织中nNOS的OD值均明显高于对照组(P<0.01)。孕鼠在术前1.5h腹腔注射L-NNA后,缺血5min、15min的胎鼠脑组织中nNOS的OD值明显低于急性缺血组相应时间点的表达水平(P<0.05);而缺血30min时虽经治疗,nNOS的OD值与急性缺血组该时间点相比差异无显著性意义(P>0.05),但均明显高于正常组(P<0.05)。③胎鼠急性缺血5min、15min、30min的脑组织缺血面积均明显高于对照组(P<0.05)。孕鼠经治疗后,胎鼠于缺血5min、15min时的缺血面积明显小于急性缺血组(P<0.05);而缺血30min时的缺血面积与急性缺血组相比P>0.05。但各时间点的缺血面积仍大于正常组(P<0.05)。
Objective:To evaluate the relationship of nNOS and fetal hypoxic-ischemic brain damage and the treatable roles of NOS inhibitor.Method:The fetal rat intrauterine asphyxia model was set up and divided into the control group, acute ischemia group, treating group(injecting L-NNA 4mg/kg in pregnant rat′s abdomen before ischemia). NO level in fetal brain and the expression of nNOSmRNA and the range of ischemia were measured.Result:①The NO levels of 5min,15min ischemia in treating group were lower than those of acute ischemia group and higher than that of control group(P<0.05).There was no different in NO level between acute ischemia group and treating group(P>0.05). But they were higher than that of control group.②The OD of nNOS in fetal rat’s brain following 5min,15min,30min ischemia were significantly higher than that in the control group(P<0.01). Injection of L-NNA 4mg/kg into pregnant rat’s abdomen before ischemia,the OD of nNOS in fetal rat’s brain following 5min,15min ischemia were significantly lower than those in acute ischemia group(P<0.05). Although through the treatment, there were no different between the OD of nNOS in fetal rat’s brain following 30 min ischemia and that in acute ischemia group(P>0.05). But they were higher than those in control group(P<0.05).③The range of ischemia in fetal rat’s brain following 5min,15min,30min acute ischemia were significantly larger than that in the control group(P<0.05).After treatment,the range of ischemia following 5min,15min ischemia were significantly smaller than those in acute ischemia group (P<0.05). There were significantly different between ischemia 5min, 15min and 30min. There was no different between the range of ischemia following 30min ischemia in treating group and that in acute ischemia group(P>0.05). But they were significantly larger than that in the control group (P<0.05).④There was a positive correlation between the expression of nNOS mRNA and the value of ischemia(P<0.01).Conclusion:nNOS leads to fetal hypoxic-ischemic brain damage.There are a positive correlation between the expression of nNOS mRNA and the severity and range of the damage.L-NNA play a protective role in acute fetal hypoxic-ischemic brain damage during certain period.
出处
《中国康复医学杂志》
CAS
CSCD
2004年第12期890-893,共4页
Chinese Journal of Rehabilitation Medicine
