Lack of 3 beta-hydroxy-delta 5-C27-steroid dehydrogenase/isomerase in fibroblasts from a child with urinary excretion of 3 beta-hydroxy-delta 5-bile acids. A new inborn error of metabolism.
1990; American Society for Clinical Investigation; Volume: 86; Issue: 6 Linguagem: Inglês
10.1172/jci114939
ISSN1558-8238
AutoresMarie S. Buchmann, E. A. Kvittingen, Hisham M. Nazer, Thirumazhisai S. Gunasekaran, Peter T. Clayton, Jan Sjövall, Ingemar Björkhem,
Tópico(s)Hormonal Regulation and Hypertension
ResumoCultured fibroblasts were shown to be capable of catalyzing the conversion of 7 alpha-hydroxy-cholesterol to 7 alpha-hydroxy-4-cholesten-3-one, an important reaction in bile acid synthesis. The apparent Km was approximately 7 mumol/liter and Vmax varied between 3 and 9 nmol/mg protein per h under the assay conditions used. The assay was used to investigate fibroblasts from a patient who presented with a familial giant cell hepatitis and who was found to excrete the monosulfates of 3 beta, 7 alpha-dihydroxy-5-cholenoic acid and 3 beta, 7 alpha, 12 alpha-trihydroxy-5-cholenoic acid in urine (Clayton, P. T., J. V. Leonard, A. M. Lawson, K. D. R. Setchell, S. Andersson, B. Egestad, and J. Sjövall. 1987. J. Clin. Invest. 79:1031-1038). In addition 7 alpha-hydroxy-cholesterol was found to accumulate in the circulation. Cultured fibroblasts from this boy were completely devoid of 3 beta-hydroxy-delta 5-C27-steroid dehydrogenase/isomerase activity. Fibroblasts from his parents had reduced activity, compatible with a heterozygous genotype. The results provide strong evidence for the suggestion that this patient's liver disease was caused by a primary defect in the 3 beta-hydroxy-delta 5-C27-steroid dehydrogenase/isomerase involved in bile acid biosynthesis.
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