Active Secretion in the Rabbit Oviduct

¹ From the Department of Embryology, Carnegie Institution of Washington, Baltimore, Maryland

Determinations of the rates of secretion and the pressures against which ligated, catheterized oviducts of Dial-urethane-anesthetized rabbits produce tubal fluid indicate this to be an active secretion of the genital tract. Secretory activity is influenced by the hormonal condition of the animal. Both secretory rate and pressure are high during estrus (av., 0.79 ml/24 hr/tube and 46.0 cm H₂O pressure) and low in late pregnancy (0.28 ml/24 hr/tube and 9.6 cm H₂O pressure). Secretory activity is severely reduced after castration (0.14 ml/24 hr/tube and 11.8 cm H₂O pressure), but this decrease can be counteracted by administration of estradiol benzoate (5 /day for 3 days). The secretory process is stimulated by pilocarpine (1.11 ml/24 hr/tube and 71.3 cm H₂O pressure). The oviduct secretion may be considered to play a vital role in the reproductive economy of the rabbit.