生物喋呤对烫伤脓毒症大鼠一氧化氮合成的影响

目的：探讨生物喋呤BH4在金黄色葡萄球菌（简称金葡菌）脓毒症中的生物学效应，阐明BH4对一氧化氮（NO）诱生的调控作用。方法：76只Wistar大鼠随机分为正常对照组（n=10)、烫伤对照组（n=10)、烫伤后金葡菌感染组（n=40)和羟基嘧啶（DAHP）拮抗组（n=16)。无菌留取动物肝、肺组织采用RT－PCR方法检测三磷酸鸟苷环水解酶I（GTP－CHI）、诱生型一氧化氮合酶（iNOS)基因表达，同时测定组织中BH4和NO的水平。结果：烫伤后金葡菌感染组动物肝、肺组织中GTP－CHI基因表达明显上调，BH4产生显著增加，iNOS mRNA表达和NO的水平亦明显升高，DAHP组GTP－CHI基因表达上调和BH4合成NO的产生亦明显下降。结论：烫伤后金葡菌感染可诱导体内BH4的合成，BH4在基因和蛋白水平调控着iNOS所介导的NO大量生成，从而对金葡菌脓毒症的病理过程起促进作用。

The effect of biopterin on nitric oxide induction in rats with postburn staphylococcus aureus sepsis

Objective To investigate the effect of biopterin on nitric oxide(NO) induction.Methods 76 male Wistar rats were divided randomly into four groups:normal control group(n=10),scald control group(n=10),postburn sepsis group(n=40),and 2,4 diamino 6 hydroxy pyrimidine(DAHP)treatment group(n=16).Tissue samples from liver and lungs were collected to determine GTP cyclohydrolase I(GTP CHI) and the expression of inducible nitric oxide synthase (iNOS)mRNA.The levels of biopterin and NO were measured.Results GTP CHI gene expression and biopterin levels elevated significantly in postburn sepsis group.The expressions of iNOS mRNA and NO were also up regulated In DAHP groupg,GTP CHI mRNA expression and biopterin induction reduced,so did the production of NO.Conclusion The infection caused by Staphylococcus aureus can induce de novo biosynthesis of biopterin.Biopterin played a role in the production of NO in turns contributing to the development of postburn sepsis.