Characterization of an in vivo hormonally regulated phosphodiesterase 3 (PDE3) associated with a liver Golgi-endosomal fraction
Characterization of an in vivo hormonally regulated phosphodiesterase 3 (PDE3) associated with a liver Golgi-endosomal fraction
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DOI：
10.1006/abbi.2000.2252
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发表时间：
2001-03-01
影响因子：
3.9
通讯作者：
Benelli, C
中科院分区：
文献类型：
--
作者：
Geoffroy, V;Fouque, F;Benelli, C
与肝脏高尔基体内体 (GE) 部分相关的体内激素调节的低 K-m cAMP 磷酸二酯酶 (PDE) 活性的生化特性已得到明确表征。对溶酶体提取物溶解的 GE 级分进行 DEAE-Sephacel 色谱分析，依次洗脱出三个活性峰（编号为 I、II 和 III），而离子交换 HPLC 则解析了五个活性峰（编号为 1、2、3、4 和 5）。根据洗脱活性对 cGMP 和所选磷酸二酯酶抑制剂的敏感性，解析了两种磷酸二酯酶异构体： cGMP 刺激和 EHNA 抑制的 PDES，在 DEAE-Sephacel 峰 I 和 HPLC 峰 2 中洗脱，cGMP、西洛酰胺和 ICI 118233 抑制的 PDE3，在 DEAE-Sephacel 峰 III 和 HPLC 峰 3、4 和 5 中洗脱，用胰岛素、四碘高血糖素和生长激素急性处理后分离的 GE 级分显示出增加与注射生理盐水的对照组相比，磷酸二酯酶活性，遗传性肥胖和高胰岛素血症大鼠的 GE 分数相对于瘦同窝小鼠的 GE 分数也是如此。在所有实验大鼠中，相对于对照动物，观察到与 DEAE-Sephacel 峰 III 以及 HPLC 峰 4 和 5 相关的 PDE3 活性增加。此外，在遗传性肥胖的 Zucker 大鼠中，相对于瘦弱的同窝大鼠，观察到 PDE 活性对西洛酰胺的敏感性增加，以及由针对脂肪组织 PDE3 的抗体免疫沉淀的 PDE 活性量增加。这些结果扩展了早期对分离肝细胞的研究，表明肝脏 PDE3 是体内由胰岛素、胰高血糖素和生长激素激活的主要（如果不是唯一的）PDE 同工型。 (C) 2001 年学术出版社。
The biochemical properties of an in vivo hormonally regulated low K-m cAMP phosphodiesterase (PDE) activity associated with a liver Golgi-endosomal (GE) fraction have keen characterized. DEAE-Sephacel chromatography of a GE fraction solubilized by a lysosomal extract resulted in the sequential elution of three peaks of activity (numbered I, II, and III), while ion-exchange HPLC resolved five peaks of activity (numbered 1, 2, 3, 4, and 5), Based on the sensitivity of the eluted activity to cGMP and selected phosphodiesterase inhibitors, two phosphodiesterase isoforms were resolved: a cGMP-stimulated and EHNA-inhibited PDES, eluted in DEAE-Sephacel peak I and HPLC peak 2 and a cGMP-, a cilostamide-, and ICI 118233-inhibited PDE3, eluted in DEAE-Sephacel peak III and HPLC peaks 3, 4, and 5, GE fractions isolated after acute treatments with insulin, tetraiodoglucagon, and growth hormone displayed an increase in phosphodiesterase activity relative to saline-injected controls, as did GE fractions from genetically obese and hyperinsulinemic rats relative to lean littermates. In all experimental rats, an increase in PDE3 activity associated with DEAE-Sephacel peak III and HPLC peaks 4 and 5 was observed relative to control animals. Furthermore, in genetically obese Zucker rats, an increase in the sensitivity of PDE activity to cilostamide and in the amount of PDE activity immunoprecipitated by an antibody to adipose tissue PDE3 was observed relative to lean littermates. These results extend earlier studies on isolated hepatocytes and show that liver PDE3 is the main if not sole PDE isoform activated by insulin, glucagon, and growth hormone in vivo. (C) 2001 Academic Press.