Hypophysectomy does not destroy the blood-testis barrier of the adult rat (Setchell, Voglmayr & Waites, 1969; Johnson, 1970), but the development of the barrier in the impubertal animal (Days 6 to 30 post partum) occurs at the same time as other changes known to depend on secretions of the anterior pituitary (Setchell, Scott, Voglmayr & Waites, 1969). Administration of oestrogens to young male rats is known to depress secretion of gonadotrophins and its effect on the development of the blood-testis barrier is investigated in this paper.
Four schedules of oestradiol benzoate injection in arachis oil were used (Table 1). At least five mice on each schedule were killed at Days 3, 15 and 25 post partum. The testes were examined for intratubular staining by acriflavine (20 mg/kg subcutaneously 5 hr before autopsy) as an indication of barrier