The distribution of 14C into several subcellular fractions of adult rat brain was studied as a function of time, following intracerebral injection of [2‐14C]mevalonic acid. As expected from previous studies, the microsomal fraction was indicated as the site of sterol biosynthesis. The myelin fraction showed a marked and early uptake of I4C‐labelled, digitonin‐precipitable material. This was assumed to be a non‐enzymic uptake of sterol intermediates. The mitochondrial fraction exhibited a rapid uptake of 14C‐labelled, nonsaponifiable material, but a very slow accumulation of 14C‐labelled, digitonin‐precipitable product. Examination of the nonsaponifiable 14C‐fractions by TLC showed a rapid appearance of labelled 4‐desmethyl sterols in the microsomal fraction. The myelin fraction selectively retained 4,4′‐dimethyl sterol but seemed to release this with time, possibly to be further metabolized by the microsomes. Examination of [14C]digitonin‐precipitable material by the dibromide method showed that although labelled 4‐desmethyl sterol appeared quite early, cholesterol itself was formed slowly in all fractions.
No takes yet. Share an insight, caveat, or question.
Ramsey et al. (1971) studied this question.
Synapse has enriched 4 closely related papers on similar clinical questions. Consider them for comparative context: