Rat ventral prostate incorporated (1- 14 C)acetate, (1- 14 C)palmitate and (1- 14 C)linoleate into different phospholipids in a time-dependent process. The rate of incorporation into total phospholipids was higher with linoleate (10.0 nmol/g) than with either palmitate (5.8 nmol/g) or acetate (4.7 nmol/g). Predominant labelling with all the radioactive substrates assayed was found in choline glycerophospholipids (PC). The radioactive profiles for linoleate in the other ventral prostate phospholipids differed from those obtained with palmitate and acetate. Specifically linoleate was incorporated into inositol glycerophospholipids plus lysoethanolamine glycerophospholipids (PI+LPE) and not into sphingomyelin (SM), while palmitate and acetate incorporated into SM but not into PI+LPE. Acetate showed the highest oxidation to CO 2 whereas no differences were observed in the radioactivity incorporated into CO 2 from a saturated (palmitate) or an essential unsaturated fatty acid (linoleate). These studies also show zinc-dependence by the acetate to CO 2 oxidation.