On the Presence of Progesterone in Blood Plasma from Normal Women

Abstract

By the criteria of ultraviolet absorbance, retention time in gas-liquid chromatography, infrared spectrometry, isotope dilution derivate analysis and recrystallization to constant specific activity, a tentative isolation and identification of progesterone in pooled blood plasma of nonpregnant women have been made. The concentration of progesterone in μg/100 ml plasma varied throughout the cycle in the following way: days 1–10 less than 0.10, days 11–15 1.60, days 16–20 1.25, and from the 21st day to the first day of the next cycle 0.44. The data are discussed in the light of current methods permitting adequate measurement of plasma progesterone in nonpregnant women.