Hierholzer K, Schöneshöfer M, Siebe H, Tsiakiras D, Weskamp P
Pflugers Arch. 1984 Apr;400(4):363-71. doi: 10.1007/BF00587533.
Kidneys of male Sprague Dawley rats have been isolated and perfused in vitro in order to study the metabolism of corticosterone (B). B is the main endogenous corticosteroid in this species. Using 3H-B and HPLC for the separation of steroid metabolites it has been possible to detect radioactive derivatives of B which have been denoted as met I, II and III. These substances were purified and compared with authentic reference hormones under different isocratic and gradient elution techniques. We observed chromatographic identity of met I with 11-dehydro-20-dihydro-B, of met II with 20-dihydro-B and of met III with 5 alpha-H-4,5-dihydro-B. From the fact that conversion of B can be observed with normal (50 g X l-1 albumin in perfusate) and elevated (75 g X l-1) colloid osmotic pressure of the recirculating perfusate it can be concluded that B gets access to the metabolic site in renal tissue not solely by glomerular filtration and tubular reabsorption. The metabolites identified presently are excreted in the urine. Metopirone increased the concentration of met I and decreased the concentration of met II. This is compatible with the concept of a stimulatory effect of metopirone on a C-20-hydroxysteroid oxidoreductase and a C-11-hydroxysteroid dehydrogenase.
为了研究皮质酮（B）的代谢，已分离并在体外灌注雄性Sprague Dawley大鼠的肾脏。B是该物种中的主要内源性皮质类固醇。使用³H-B和高效液相色谱法（HPLC）分离类固醇代谢物，已能够检测到B的放射性衍生物，分别命名为代谢物I、II和III。这些物质经过纯化，并在不同的等度洗脱和梯度洗脱技术下与标准参考激素进行比较。我们观察到代谢物I与11-脱氢-20-二氢-B具有色谱同一性，代谢物II与20-二氢-B具有色谱同一性，代谢物III与5α-H-4,5-二氢-B具有色谱同一性。鉴于在再循环灌注液的正常（灌注液中50 g·L⁻¹白蛋白）和升高（75 g·L⁻¹）胶体渗透压下都能观察到B的转化，可以得出结论，B并非仅通过肾小球滤过和肾小管重吸收进入肾组织的代谢部位。目前鉴定出的代谢物会随尿液排出。甲吡酮增加了代谢物I的浓度，降低了代谢物II的浓度。这与甲吡酮对C-20-羟基类固醇氧化还原酶和C-11-羟基类固醇脱氢酶具有刺激作用的概念相符。
