Falls J G, Blake B L, Cao Y, Levi P E, Hodgson E
Department of Toxicology, North Carolina State University, Raleigh 27695, USA.
J Biochem Toxicol. 1995 Jun;10(3):171-7. doi: 10.1002/jbt.2570100308.
Hepatic flavin-containing monooxygenase (FMO) activity of microsomes from adult CD-1, Swiss-Webster, C57BL/6, and DBA/2 mice was found to be significantly higher in females than in males. Based on protein and mRNA levels in CD-1 mice, FMO forms responsible for the gender difference in FMO activity were FMO1 and FMO3. FMO1 expression was two to three times higher in female mice compared with males; FMO3, however, which was expressed at levels equivalent to FMO1 in female mice, was not detected in males. The expression of FMO5 was approximately equal in both sexes. FMO2 and FMO4 transcripts were not evident in hepatic mRNA from mice. Protein and mRNA levels appear to be coregulated with regard to gender-selective or gender-specific expression of FMO1 or FMO3, respectively. FMO5, which demonstrates no gender-selective expression in mice, may be regulated by different mechanisms. Examination of protein levels among Swiss-Webster, C57BL/6, and DBA/2 strains revealed a gender-dependent expression of FMO isozymes identical to the CD-1 strain.
研究发现，成年CD-1、瑞士 Webster、C57BL/6和DBA/2小鼠微粒体中的肝含黄素单加氧酶（FMO）活性在雌性小鼠中显著高于雄性小鼠。基于CD-1小鼠中的蛋白质和mRNA水平，导致FMO活性存在性别差异的FMO形式为FMO1和FMO3。雌性小鼠中FMO1的表达比雄性小鼠高两到三倍；然而，FMO3在雌性小鼠中的表达水平与FMO1相当，在雄性小鼠中未检测到。FMO5在两性中的表达大致相等。FMO2和FMO4转录本在小鼠肝脏mRNA中不明显。蛋白质和mRNA水平似乎分别在FMO1或FMO3的性别选择性或性别特异性表达方面受到共同调节。FMO5在小鼠中没有性别选择性表达，可能受不同机制调节。对瑞士 Webster、C57BL/6和DBA/2品系的蛋白质水平进行检测，发现FMO同工酶的性别依赖性表达与CD-1品系相同。
