Lo Y H, Sheff M F, Latif S A, Ribeiro C, Silver H, Brem A S, Morris D J
Department of Pathology and Laboratory Medicine, Miriam Hospital, Providence, RI 02906, USA.
Hypertension. 1997 Jan;29(1 Pt 2):500-5. doi: 10.1161/01.hyp.29.1.500.
We have previously shown that human urine contains substances that, like glycyrrhetinic acid, inhibit 11 beta-HSD1. We have named these substances "glycyrrhetinic acid-like factors" or GALFs. We now have found that human urine contains measurable quantities of both 11 beta(HSD1)- and 11 beta(HSD2)-GALF inhibitory substances. Both are markedly elevated in pregnancy. Their chemical and high-performance liquid chromatography (HPLC) characteristics suggest that several of the GALFs are steroidal. Large quantities of neutral 11 beta(HSD1)- and 11 beta(HSD2)-GALFs can be extracted directly from urine into ethyl acetate, yielding fraction EA1. Hydrolysis of the GALFs remaining in the aqueous phase by beta-glucuronidase markedly increases the total amounts of GALFs, with the majority now being ethyl acetate extractable (fraction EA2). These EA2 post-hydrolysis GALFs can be separated by HPLC resulting in at least six components with inhibitory activity against each isoenzyme. Only two GALF peaks are active against both 11 beta-HSD1 and 11 beta-HSD2. The others are peaks with specific 11 beta(HSD1)- and 11 beta(HSD2)-GALF inhibitory activity. The GALFs in the same posthydrolysis EA2 extract are also inhibitory toward the 11 beta-HSD1 that is present in vascular smooth muscle where they may play a role in the mechanisms controlling blood pressure. We have also found that 11 beta-HSD2 is selectively inhibited by 5 alpha- (but not by 5 beta-) reduced steroids. GC-MS analysis of the 11 beta(HSD2)-GALFs in EA2 is now being performed to determine whether this group includes 3 alpha,5 alpha-ring A-tetrahydro-reduced derivatives of steroids.
我们之前已经表明，人类尿液中含有一些物质，这些物质如同甘草次酸一样，能够抑制11β-羟基类固醇脱氢酶1（11β-HSD1）。我们将这些物质命名为“甘草次酸样因子”（GALFs）。现在我们发现，人类尿液中含有可测量数量的11β（HSD1）-GALF和11β（HSD2）-GALF抑制性物质。在孕期，这两种物质的含量均显著升高。它们的化学特性和高效液相色谱（HPLC）特征表明，几种GALFs是甾体类物质。大量的中性11β（HSD1）-GALF和11β（HSD2）-GALF可直接从尿液中萃取到乙酸乙酯中，得到萃取物EA1。用β-葡萄糖醛酸酶水解水相中剩余的GALFs，可显著增加GALFs的总量，此时大部分GALFs可被乙酸乙酯萃取（萃取物EA2）。这些水解后的EA2 GALFs可通过HPLC分离，得到至少六种对每种同工酶具有抑制活性的成分。只有两个GALF峰对11β-HSD1和11β-HSD2均有活性。其他峰则具有特定的11β（HSD1）-GALF和11β（HSD2）-GALF抑制活性。同一水解后EA2萃取物中的GALFs对血管平滑肌中存在的11β-HSD1也有抑制作用，它们可能在血压控制机制中发挥作用。我们还发现，11β-HSD2被5α-（而非5β-）还原类固醇选择性抑制。目前正在对EA2中的11β（HSD2）-GALFs进行气相色谱-质谱联用（GC-MS）分析，以确定该组物质是否包括类固醇的3α,5α-环A-四氢还原衍生物。
