| Autor: |
Y, Amuro, W, Yamade, A, Maebo, T, Hada, K, Higashino |
| Rok vydání: |
1985 |
| Předmět: |
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| Zdroj: |
Biochimica et biophysica acta. 837(1) |
| ISSN: |
0006-3002 |
| Popis: |
The formation of lithocholic and isolithocholic acids from 3-keto-5 beta-cholanoic acid by human liver cytosol was examined in vitro. Liver cytosol was incubated at various pH levels with 3-keto-5 beta-cholanoic acid in a phosphate buffer containing NADPH or NADH; the products formed were analyzed by gas chromatography. Results showed that human liver cytosol reduced 3-keto-5 beta-cholanoic acid to lithocholic acid at a pH level of 7.0 or above and to isolithocholic acid at a pH level of 6.0 or below when NADPH was used as a coenzyme, and it was reduced to isolithocholic acid only when NADH was used. Furthermore, two peaks for the reducing enzymes could be clearly found by column chromatography of Affi-Gel Blue. These results indicate that human liver cytosol contains two enzymes acting on reduction of 3-keto-5 beta-cholanoic acid to lithocholic and isolithocholic acids, which are dependent on the pH level and the use of NADPH or NADH in vitro. Since the 3 beta-dehydrogenation was inhibited by the addition of pyrazole, an alcohol dehydrogenase inhibitor or ethanol, and the major peak of 3 beta-hydroxysteroid dehydrogenase coincided with the peak of alcohol dehydrogenase on Affi-Gel Blue chromatography, at least some of the cytosolic 3 beta-hydroxysteroid dehydrogenase seemed to be identical to or to have characteristics similar to alcohol dehydrogenase. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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