Estradiol 17β and pituitary responsiveness to luteinizing hormone releasing factor in the rat: A study using rectangular pulses of estradiol 17β monitored by non chromatographic radioimmunoassay

Abstract

Plasma concentrations of oestradiol-17β were measured by a non-chromatographic radioimmunoassay during the oestrous cycle, after the s.c. injection of 2.5 or 10 μg oestradiol benzoate (OB), or the s.c. implantation of Silastic capsules containing crystalline oestradiol-17β. The profile of endogenous plasma oestradiol-17β concentrations was similar to that reported by other workers, and lay between the concentrations produced b the low and high doses of OB. The rectangular pulses of increased plasma oestradiol concentrations, produced during the period of implantation of the Silastic capsules, were used to determine the time taken for oestradiol-17β to exert its facilitatory effect on the gon..