Quantitative Methods for Determining Progestins in Corpora Lutea, Ovaries, and Adrenals of the Cow and Sow Using Progesterone-4-C14 as a Measure of Recovery of Extracted Hormone

Abstract

A quantitative method is de-scribed for the chemical assay of progesterone and [DELTA]4-pregnene-20[beta]-ol-3-one. The tissues were extracted with ethyl acetate, followed by vacuum distillation and partitioning of the residue between Skellysolve B-70% methanol and benzene. The progestins were separated and further purified by paper chromatography using the Bush Skellysolve B-95% methanol system, eluted, and rechromatographed in the same system. Progesterone-4-C14 (0.08 [mu]g; 3,500 c.p.m.) was added at the time of initial extraction to estimate recovery of progesterone during each assay. The radiochemical purity of the compound was 93-94%. About 4% of the radioactivity remained in the tissue during initial extraction and approximately 16% was lost during each elution of the paper chromatograms. Average recovery of progesterone-4-C14 was 40% for 224 samples of cow tissues (standard error 0.7%) and 51% for 114 samples of sow tissues (standard error 1.1%). No [DELTA]4-pregnene-20[beta]-ol-3-one was detected in sow tissues.