Initiation of the oestrous cycle in the ewe by infusions of PGF 2 alpha-to the autotransplanted ovary

Seasonal variation in oestrus, the secretion of oestrogen and progesterone and LH levels before ovulation in the ewe

“…The changes in the secretion of progesterone and oestradiol and the concentration of LH on the seven occasions when luteal regression was considered to have been followed by ovulation are similar to those described following luteal regression induced in normal animals with PGF-2a (Barrett et al, 1971 ;Chamley et al, 1972) or with a synthetic analogue (Baird & Scaramuzzi, 1976). In the ewe, progesterone and oestradiol-17ß are derived exclusively from the corpus luteum and Graafian follicle(s) respectively so that their secretion reflects the activity of these ovarian compart¬ ments (Baird & Scaramuzzi, 1976).…”

Proceedings of the Australian Society for Reproductive Biology

“…This confirms the finding of Barrett et al (1971). Following the lh peak, E2 secretion returned to baseline in both cases.…”

Relation Between Luteal Regression and So-called Counter Current Mechanism in the Cow: Verification from PGF2.ALPHA. Concentrations in Ovarian Arterial, Uterine Venous and Jugular Venous Blood following PGF2.ALPHA. Loading.

“…The peak level in the artery at 2 min after the start of infusion was 2 times as high as the level in the jugular vein. The concentration was kept lower than those veins [1,[3][4][5]8]. …”