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Enzymatic and non-enzymatic defense mechanisms against active oxygen in the perinatal period

围产期针对活性氧的酶和非酶防御机制

基本信息

批准号：
03454266
负责人：
ONISHI Shoju
金额：
$ 3.78万
依托单位：
Kagawa Medical School
依托单位国家：
日本
项目类别：
Grant-in-Aid for General Scientific Research (B)
财政年份：
1991
资助国家：
日本
起止时间：
1991 至 1992
项目状态：
已结题

项目摘要

1. The lung activities of the antioxidant enzymes (Cu, Zn-superoxide dismutase and glutathione peroxidase) were estimated on 25 autopsied cases human fetuses from 12 to 41 gestational weeks. The enzyme activities per protein concentration did not significantly change during the prenatal period but, if expressed per lung wet weight, they did show a tendency to increase from 25 gestatinal weeks.2. The bilirubin metabolism during the phototherapy for neonatal hyperbilirubinemia has been extensively studies, while the kinetics of biliverdin, one of the photooxidation products of bilirubin, has scarcely been clarified. Plasma biliverdin concentrations increased gradually after the initiation of photoirradiation, similarly as in the in vitro experiments. The relationship between the increment of the plasma biliverdin concentration during 24 hours following the start of photothrapy and the age in days of the very beginning of phototherapy revealed that the plasma biliverdin concentrations exp … More onentially decreased with age. It was concluded that the increment of the plasma biliverdin concentrations during 24 hours following the start of phototherapy reflected postnatal maturation of the biliary excretion from the hepatocyte.3. The active oxygen producing power of umbilical and maternal erythrocytes against oxidative stress was investigated using the chemiluminescence probe Cypridinal luciferin analogue (MCLA) for superoxide anion (O_2^-) generation. It was found that erythrocytes in the umbilical venous blood revealed a 2.1-fold greater maximum chemiluminescence compared to those in the maternal blood, and that chemiluminescence of the umbilical venous blood was significantly lower than that of the maternal blood upon completion of measurements.4. We examined active oxygen products during resuscitation after asphyxial load in five newborn piglets with reference to the method reported by Takahashi et al. First, this method was confirmed to be capable of measuring active oxygen in vivo and in situ. The animals were divided into two groups. was performed with 100% oxygen in one group and 21% oxygen in another group. The mean relative maximal lung surface chemiluminescence was 163(〕SY.+-.〔)47 counts in the 100% oxygen group and 47(〕SY.+-.〔)33.4 counts in the 21% oxygen group. The difference between the two groups Resuscitation was statistically significant at a level of 3% or less. This study proved that a large amount of active oxygen is produced even during ordinary resuscitation, and this fact emphasizes the necessity of sufficient precaution in oxygen administration. Furthermore, the antioxidant effect of bilirubin and urate was investigated, but the latter only proved to have a protective effect on active oxygen. Less

1. 测定了25例12 ~ 41孕周死亡胎儿肺中抗氧化酶（铜、锌超氧化物歧化酶和谷胱甘肽过氧化物酶）的活性。每蛋白质浓度的酶活性在产前期间没有显著变化，但从妊娠25周开始，每肺湿重表达的酶活性有增加的趋势。新生儿高胆红素血症光疗过程中胆红素的代谢已被广泛研究，而胆红素光氧化产物之一的胆绿素的动力学尚不清楚。血浆胆绿素浓度在开始光照射后逐渐升高，与体外实验相似。光疗开始后24小时内血浆胆绿素浓度的增加与光疗开始时的年龄之间的关系表明，血浆胆绿素浓度随年龄的增长呈下降趋势。由此得出结论，光疗开始后24小时内血浆胆绿素浓度的增加反映了出生后肝细胞胆汁排泄的成熟。采用化学发光探针环荧光素类似物（MCLA）研究了脐带红细胞和母体红细胞对氧化应激产生活性氧的能力。结果发现，脐血静脉血红细胞的最大化学发光量是母体血红细胞的2.1倍，测量完成后，脐血静脉血的化学发光量明显低于母体血。我们参照Takahashi等人报道的方法，检测了5头新生仔猪窒息负荷后复苏期间的活性氧产物。首先，证实了该方法能够在体内和原位测量活性氧。这些动物被分成两组。一组给氧100%，另一组给氧21%。平均相对最大肺表面化学发光为163(]SY.+-。100%含氧组47例，21%含氧组47(]SY.+-.[)33.4例。两组间的差异有统计学意义，在3%及以下的水平。本研究证明，即使在普通复苏过程中也会产生大量的活性氧，这一事实强调了给氧时充分预防的必要性。此外，研究了胆红素和尿酸盐的抗氧化作用，但后者仅证明对活性氧有保护作用。少