THE UPTAKE OF (6,7-3H) 17β-OESTRADIOL BY TISSUES OF THE DOMESTIC FOWL DURING AN OVULATION CYCLE

ABSTRACT The uptake of radioactivity by various tissues of the domestic fowl has been studied following a single intravenous dose, at different times during the ovulatory cycle. It has been found that the pituitary gland showed significant cyclical accumulations of radioactivity, when calculated in terms of dpm/mg wet weight, at different stages in the ovulatory cycle, the greatest accumulation being in the period 12–16 hours before the expected ovulation. The results are discussed in relation to the role of oestrogens in the timing of ovulation. It is proposed that oestradiol acts as a major regulator of the timing of ovulation in the domestic fowl.