| Abstract: | Placental mince of three ewes at each of days 80, 110 and 140 of gestation was incubated in Krebs-Ringer bicarbonate buffer solution (pH 7.4) plus 200 mg% glucose to which ¹⁴C-labeled sodium acetate, ovine luteinizing hormone, adenosine triphosphate, reduced nicotinamide adenine dinucleotide phosphate and 3',5'-cyclic adenosine monophosphate were added. The incubation was carried out for two hours at 37°C and under a gaseous atmosphere of 5% CO₂ and 95% air. Progesterone, estrone and estradiol-17β were isolated and purified by two thin layer chromatography steps, acetylation, paper chromatography and recrystallization with carriers to a constant specific radioactivity. Chemical purity of the isolated and the carrier hormones was established by mass spectrometry. Liquid scintillation spectrometry data indicated that ¹⁴C-labeled acetate was incorporated into progesterone but not estrone and estradiol-17β, of the placental mince at the three stages of gestation. The overall average of the radioactivity incorporated into progesterone was approximately doubled at days 110 and 140 compared to day 80 of gestation. |
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