Identification of 24-Dehydrocholesterol in Human Blood Vessels Following MER-29 Therapy. ∗

Summary and Conclusions

This report indicates that 24-dehydrocholesterol accumulated in human blood vessel walls and it seems probable that treatment with MER-29 was responsible. Although 24-dehydrocholesterol was not demonstrable in the extensive atheromatosis which covered 90% of the aorta, it accounted for 13-16% of the sterols in normal aortic wall. The magnitude of accumulation of 24-dehydrocholesterol in normal aortic wall would not have been apparent if assays had been performed on sterols extracted from the aorta as a whole because the sterols of normal wall would have been greatly diluted by atheromatosis lipid containing no 24-dehydrocholesterol. Because these vessels were examined only 79 days after onset of therapy with MER-29, the presence of 24-dehydrocholesterol in normal wall but not in atheromas seems best explained by a more rapid accumulation in normal wall. However, it is possible that 24-dehydrocholesterol may only accumulate in normal vessel walls.