Progesterone Levels in Ovarian Venous Effluent of the Nonpregnant Sow3

Abstract

Seventy-four ovarian venous blood samples were obtained from 18 sows by cannulation of an ovarian vein and collection of blood. Progesterone levels in blood plasma samples were measured by a double-isotope derivative method involving conversion of progesterone to 20β-hydroxy-Δ⁴-pregnene-3-one (20β-ol) with sodium borohydride-³H. Progesterone levels increased from 0.03± 0.01 meg./ml. of plasma on the first day of estrus to 1.07±0.13 meg./ml. on days 10 to 12 of the estrous cycle. Thereafter, the level decreased to 0.04±0.01 meg./ml. on days 19 to 21 of the cycle. Two ultraviolet absorbing compounds other than progesterone were found in the plasma samples. These probably were not 20β-ol or its 20_a-epimer, 17_a-hydroxyprogesterone, androstenedione or pregnenolone. Copyright © 1965. American Society of Animal Science . Copyright 1965 by American Society of Animal Science