Mancini M A, Chatterjee B, Roy A K
Department of Cellular and Structural Biology, University of Texas Health Sciences Centre, San Antonio 78284.
J Histochem Cytochem. 1991 Apr;39(4):401-5. doi: 10.1177/39.4.1706374.
Hepatocytes situated at pericentral and periportal zones of the liver lobule show differences in the expression of several liver-specific genes, such as androgen-inducible alpha 2u globulin and androgen-repressible senescence marker protein-2 (SMP-2). A marked temporal difference in the expression of these two androgen-regulated genes has also been observed. The liver of the pre-pubertal male rat is insensitive to androgen, and during this period hepatocytes synthesize only SMP-2. During young adult life (greater than 40 days), the liver becomes androgen sensitive and concomitant synthesis of alpha 2u globulin and repression of SMP-2 occur. In the senescent male rat (greater than 750 days), the liver again becomes androgen insensitive when the decline in alpha 2u globulin is accompanied by an increase in SMP-2 synthesis. In this article we present results to show a correlation between the temporal and spatial (intralobular) changes in the expression of the androgen-inducible alpha 2u globulin and the androgen-repressible SMP-2 in rat hepatocytes. Results indicate that the temporal changes in hepatic androgen sensitivity are dictated by the intralobular location of the hepatocytes. Hepatocytes located around the central vein (pericentral/perivenous) may benefit from a paracrine advantage for the expression of a subset of genes, including the gene for the androgen receptor.
位于肝小叶中央周围和门周区域的肝细胞在几种肝脏特异性基因的表达上存在差异，比如雄激素诱导的α2u球蛋白和雄激素抑制的衰老标记蛋白2（SMP-2）。这两种雄激素调节基因的表达也存在明显的时间差异。青春期前雄性大鼠的肝脏对雄激素不敏感，在此期间肝细胞仅合成SMP-2。在成年早期（大于40天），肝脏变得对雄激素敏感，同时会合成α2u球蛋白并抑制SMP-2的合成。在衰老的雄性大鼠（大于750天）中，当α2u球蛋白下降伴随着SMP-2合成增加时，肝脏再次变得对雄激素不敏感。在本文中，我们展示的结果表明，大鼠肝细胞中雄激素诱导的α2u球蛋白和雄激素抑制的SMP-2表达的时间和空间（小叶内）变化之间存在相关性。结果表明，肝脏雄激素敏感性的时间变化取决于肝细胞在小叶内的位置。位于中央静脉周围（中央周围/静脉周围）的肝细胞可能因旁分泌优势而有利于包括雄激素受体基因在内的一组基因的表达。
