Figure 1
Effect of E 2 BSA on the secretory patterns of LH and GnRH. (a) Secretory patterns of LH and GnRH in individual ewes during the acute inhibition of LH induced by E2BSA. Patterns of LH (open diamonds) and GnRH (closed squares) in individual ewes treated with an im bolus of 12 mg E2BSA (hour 0). GnRH and LH were measured in samples of pituitary portal and jugular blood, respectively, withdrawn continuously and separated into 10-min fractions, from 4 h before to 4 h after treatment. (*) is indicative of a pulse. (b) E2BSA decreased secretion of LH without affecting the secretory patterns of GnRH during the acute inhibition of LH secretion. Mean plasma rate of GnRH, number of pulses of GnRH and amplitude of pulses (right panel) were measured in pituitary portal blood whereas mean LH, number of pulses and amplitude of pulses of LH (left panel) were measured in jugular blood. Samples were collected at 10-min intervals, from 4 h before (open bars) to 4 h after treatment (solid bars). Data are presented as the mean ± SEM. Comparisons were made within periods. a, b differ (P < 0.02); c, d differ (P < 0.01).