Ogura Y, Ayaki Y
Biol Chem Hoppe Seyler. 1987 Jul;368(7):813-7. doi: 10.1515/bchm3.1987.368.2.813.
The formation of alpha-muricholic acid and beta-muricholic acid from chenodeoxycholic acid was comparatively investigated in livers isolated from normal, streptozotocin-diabetic, and insulin-treated diabetic rats. [24-14C]Chenodeoxycholic acid or [24-14C]alpha-muricholic acid was infused into the perfused livers. There was no difference in biliary excretion of 14C among the different groups of rats after the infusion of each 14C-labelled bile acid. Biliary [14C]bile acids were chromatographed on a thin-layer plate and the distribution of radioactivity on the plate was measured by radioscanning. In the diabetic group, the formation ratio of alpha-muricholic acid and beta-muricholic acid from [24-14C]chenodeoxycholic acid and also that of beta-muricholic acid from [24-14C]alpha-muricholic acid were much smaller than in the normal group. Treatment of the diabetic group with insulin cancelled the difference in the infusion of each [24-14C]bile acid. The results indicate that not only 6 beta-hydroxylation of chenodeoxycholic acid to alpha-muricholic acid but also 7-epimerization of the latter acid to beta-muricholic acid is suppressed in an insulin-deficient state in rats.
在从正常大鼠、链脲佐菌素诱导的糖尿病大鼠和胰岛素治疗的糖尿病大鼠分离的肝脏中，对鹅去氧胆酸形成α-鼠胆酸和β-鼠胆酸的过程进行了比较研究。将[24-¹⁴C]鹅去氧胆酸或[24-¹⁴C]α-鼠胆酸注入灌注肝脏。在注入每种¹⁴C标记的胆汁酸后，不同组大鼠的¹⁴C胆汁排泄没有差异。将胆汁中的[¹⁴C]胆汁酸在薄层板上进行色谱分析，并通过放射性扫描测量板上的放射性分布。在糖尿病组中，由[24-¹⁴C]鹅去氧胆酸形成α-鼠胆酸和β-鼠胆酸的比例，以及由[24-¹⁴C]α-鼠胆酸形成β-鼠胆酸的比例，均远低于正常组。用胰岛素治疗糖尿病组可消除每种[24-¹⁴C]胆汁酸注入时的差异。结果表明，在大鼠胰岛素缺乏状态下，不仅鹅去氧胆酸6β-羟基化生成α-鼠胆酸受到抑制，而且后者酸7-差向异构化生成β-鼠胆酸也受到抑制。
