Ovarian arterial blood velocity measured with Doppler ultrasonic transducers in conscious ewes

Abstract

Changes in the mean velocity of ovarian arterial blood flow during the oestrous cycle were monitored in 5 ewes by the use of doppler ultrasonic transducers chronically implanted around the ovarian arteries. In arteries supplying ovaries with a corpus luteum (CL), the velocity was minimal from Day -1 to Day 2 inclusive (Day 0 = day of oestrus), increased steadily until Day 13 (-4) and then declined precipitously. In contralateral arteries supplying ovaries without a CL, the velocity remained at a consistently low level throughout the oestrous cycle. In each ewe, arterial blood velocity to the ovary with a CL and progesterone levels in peripheral plasma were highly correlated; within-individual correlations falling between r = 0.830 (P < 0.001, n = 15) and r = 0.936 (P < 0.001, n = 15). The changes in the velocity of the arterial supply to the ovulatory ovary and the pattern to that for weight of luteal tissue in similar ewes.