Chemical Estimation of Progesterone in the Blood of Cattle, Sheep, and Goats

Abstract
A method is described for determination of progesterone in blood based on extraction and partition between organic solvents, paper partition chromatography, and UV absorption spectrophotometry. Progesterone was found in a pregnant goat in blood leaving an ovary that contained a corpus luteum and in one containing a Graafian follicle only. It could not be detected in the venous drainage of the uterine horns, gravid and non-gravid, in 2 pregnant goats, nor in the peripheral blood of several of the large domesticated animals. After a single subcutaneous injection of 1 g progesterone a peak concentration was seen about 2 hours after administration. Subcutaneous injection of the hormone for several days resulted in a detectable concentration in the peripheral blood of a pregnant animal. In a young dairy bull plasma progesterone levels above 1 [mu]g/ml were maintained for 24 hours for 3 consecutive days by daily injections of 1 g. In dairy heifers subcutaneous injections of 100 mg daily showed maximum levels within 1.5 hours and disappearance within 4 hours. When microcrystals were suspended in water, the maximal level attained for plasma progesterone was lower, but measurable amounts were present after 8 hours.