Biosynthesis of [14C]arachidonic acid from [14C]linoleate in primary cultures of rat Sertoli cells.

The conversion of [14C]linoleate to [14C]arachidonate by rat Sertoli cells was established by use of primary cultures. Most of the 14C from [1-14C]linoleate was located in C-3 of the synthesized arachidonate, indicating that the labeled tetraene had originated largely by elongation and desaturation of the intact labeled substrate rather than by mere addition of 14C-acetate generated by bio-oxidation of the radioactive substrate to an already existing 18-carbon precursor. Although a relatively small amount of 14C was present in 18:3 omega 6 and a relatively large amount of 14C was present in 20:2, it was not possible from these data to establish the relative importance of 20:2 in the biosynthesis of arachidonic acid in rat Sertoli cells.