The metabolism of polyunsaturated fatty acids in rat Sertoli and germinal cells.

The metabolism of [1-14C] linoleic, [1-14C] arachidonic and [3-14C] docosa-4,7,10,13,16-pentaenoic acids was investigated after intratesticular injection of the labeled compounds and isolation of rat Sertoli and germinal cell. Following injection of either 14C-linoleate or 14C-arachidonate, the specific activity (sp act) of docosa-4,7,10,13,16-pentaenoic acid of Sertoli cells was greater than that of the germinal cells. The data suggest that the Sertoli cells are more active in the biosynthesis of the 22-carbon pentaene than the germinal cells. Differences between these 2 cell types were also noted in the distribution of the incorporated 14C among the various lipid classes. Following intra-testicular injection of 14C-docosapentaenoic acid, a greater proportion of the recovered 14C in Sertoli cells than in germinal cells was present in 20-carton fatty acids, suggesting a greater activity in Sertoli cells in the metabolism of the pentaene. The major portion of the recovered 14C in both cell types was present in triacylglycerols during early time periods and in phospholipids after 24 hr. The possibility of transfer of biosynthesized docosapentaenoic acid from Sertoli to germinal cells is discussed.