Figure 3
Secretory pattern of LH in individual ewes showing the effect of a high dose of E 2 BSA on the preovulatory-like surge of LH induced by E 2 . In a preliminary study the magnitude of the LH surge in response to E2 was determined; ewes were ranked based in the mean LH during the surge induced by E2, then assigned to either a high (LH profiles in the left panel) or a low (LH profiles in the right panel) E2-responsive group (n = 6 per group). Approximately one month later, ewes (n = 12) were given an im injection of 25 μg E2 and then assigned alternatively within each responsive group, to receive an im injection of 60 mg E2BSA (open squares) 8 h after injection of E2 or saline solution (placebo; closed diamonds). The negative impact to E2BSA on the massive release of LH induced by E2 was more pronounced in ewes classified as highly responsive to E2.