标题:Elimination of cholesterol as cholestenoic acid in human lung by sterol 27-hydroxylase: evidence that most of this steroid in the circulation is of pulmonary origin
出版社:American Society for Biochemistry and Molecular Biology
摘要:Human alveolar macrophages have exceptionally high capacity to convert cholesterol into 27-hydroxycholesterol and cholestenoic acid by the sterol 27-hydroxylase mechanism. It is shown here that the human lung has a higher content of 27-hydroxycholesterol relative to cholesterol than any other organ. In order to evaluate the importance of the sterol 27-hydroxylase mechanism for cholesterol homeostasis in the lung, the production of cholestenoic acid by human lung was investigated. Removal of one lung reduced the level of cholestenoic acid in the circulation by 48 ± 4% ( P P The present results suggest that the sterol 27-hydroxylase in the lung is responsible for at least half of the total flux of 27-oxygenated cholesterol metabolites to the liver and that this enzyme system may be of importance for cholesterol homeostasis in the lung. —Babiker, A., O. Andersson, D. Lindblom, J. van der Linden, B. Wiklund, D. Lütjohann, U. Diczfalusy, and I. Björkhem. Elimination of cholesterol as cholestenoic acid in human lung by sterol 27-hydroxylase: evidence that most of this steroid in the circulation is of pulmonary origin. J. Lipid Res. 1999. 40: 1417–1425.