Progesterone secretion and ovarian blood flow in the pregnant rat

A venous outflow technique was used to monitor the rates of ovarian blood flow and progesterone secretion simultaneously during periods of 2-3 h in nine rats pregnant for 16 days and anaesthetized with sodium pentobarbitone. The rate of ovarian blood flow was 0 x 460 +/- 0 x 135 (S.D.) ml/min and that of progesterone secretioin was 27 x 2 +/- 7 x 0 microgram/h per ovary. Within rats, progesterone secretion was unrelated to the rate of ovarian blood flow (common correlation coefficient, r = 0 x 136; degrees of freedom = 61; P, not significant) but the latter was inversely related to the arterio-venous difference in the concentratioin of progesterone (r = --0 x 731; P < 0 x 01).