Himeno S, Takekawa A, Toyoda H, Imura N
Department of Public Health, School of Pharmaceutical Sciences, Kitasato University, Tokyo, Japan.
Biochim Biophys Acta. 1993 Jun 25;1173(3):283-8. doi: 10.1016/0167-4781(93)90125-w.
Glutathione peroxidase (GSH-Px), a selenocysteine-containing enzyme, is generally considered to be important in protecting animals from oxidative injury. However, guinea pigs have very low GSH-Px activity in major tissues such as liver and kidney, while the activity in the erythrocytes is as high as that of mice or rats. The present study attempted to clarify which step in the gene expression of GSH-Px is responsible for the tissue specific regulation of GSH-Px activity in guinea pigs. Northern blot analysis showed clear signals of GSH-Px mRNA in the reticulocytes and erythroblast-enriched bone marrow cells of guinea pigs, while it was barely detectable in the liver, kidney and heart. Using the nuclear run-on assay, we confirmed that the difference in GSH-Px mRNA levels among tissues of guinea pigs results primarily from the difference in the transcription rate of the GSH-Px gene. Thus, the guinea pig may be a good model for studying the factors regulating the tissue-specific gene expression of this selenoenzyme as well as its essential role.
谷胱甘肽过氧化物酶（GSH-Px）是一种含硒代半胱氨酸的酶，通常被认为在保护动物免受氧化损伤方面起着重要作用。然而，豚鼠的肝脏和肾脏等主要组织中的GSH-Px活性非常低，而红细胞中的活性则与小鼠或大鼠的一样高。本研究试图阐明GSH-Px基因表达的哪个步骤导致了豚鼠中GSH-Px活性的组织特异性调节。Northern印迹分析显示，在豚鼠的网织红细胞和富含成红细胞的骨髓细胞中可清晰检测到GSH-Px mRNA信号，而在肝脏、肾脏和心脏中几乎检测不到。通过核转录分析，我们证实豚鼠组织间GSH-Px mRNA水平的差异主要源于GSH-Px基因转录速率的差异。因此，豚鼠可能是研究调节这种含硒酶组织特异性基因表达的因素及其重要作用的良好模型。
