METABOLISM OF DOLICHOL, DOLICHOIC ACID AND NORDOLICHOIC ACID IN CULTURED-CELLS

The uptake and metabolism of [1-C-14]-labelled dolichol, dolichoic aci d and nordolichoic acid were investigated in MDCK and HepG2 cells. Eac h of the three isoprenoids, bound to human serum albumin, was taken up effectively. None of the compounds was broken down in HepG2 cells, al though these converted dolichol into fatty acid esters. In MDCK cells dolichoic acid gave rise to the formation of [C-14]CO2 and radiolabell ed formic acid, indicating that dolichoic acid can be broken down by a lpha-oxidation. Dolichoic acid was also converted to a mixture of pola r compounds, possibly polyols. MDCK cells generated radiolabelled CO2 from nordolichoic acid, presumably through beta-oxidation, although we could not find any labelled propionic acid. No oxidative breakdown of dolichol was found, apparently due to the lack of or very low convers ion to dolichoic acid. (C) 1997 Elsevier Science B.V.