FATTY ACID BIOSYNTHESIS IN THE TESTIS OF THE HUMAN FETUS DURING THE FIRST TRIMESTER

testis are not available. The purpose of this study was to investigate the ability of the testis of the human fetus during the first trimester to synthesize fatty acids from labelled substrates. The compounds purchased from the Applied Science Laboratory, State College, Pennsylvania, were 99 % pure [1-14C]linoleic acid (all cis; sp. act., 52\m=.\5mCi/mmol) and 99 % pure [1-14C]arachidonic acid (all cis; sp. act., 52\m=.\5mCi/mmol); [1,2-14C]sodium acetate (sp. act54.m, Ci/mmol) was received from New England Nuclear Corp., Boston, Massachusetts. Undamaged abortuses were obtained from the abortion clinic at Freedmen's Hospital, Howard University, and the ages of the fetuses were determined from cro\p=m-\n-rump measurement. Abortions were performed by injection of hyper-tonic saline solution (20%) into the amniotic fluid, usually between 12 and 16 weeks of gestation, and generally occurred within 10 to 12 hr after injection. The testes were carefully removed, cleaned and weighed, and a portion of the tissue was used for histological examination in initial studies to confirm the characteristics of a normal human fetal testis. Histological examination of the fetal testes at 12 to 16 weeks of gestation showed well-developed interstitial cells and sex cords. Every effort was made to initiate incubation studies within a few hours after abortion; on occasion, however, the testes were removed, cleaned, weighed and stored at 70°C for later analysis. We have observed no significant differences in fatty acid biosynthesis in tissues stored for up to 60 days at — 70°C. In each incubation study, 5 µ linoleic or arachidonic acid or 40 µ. sodium acetate were used. Linoleic or arachidonic acid was first mixed in a small quantity of propylene glycol and then added to the incubation media. Sodium acetate was added directly to the media. The incubation mixture contained i