Transducer probe for the measurement of oestradiol-induced changes in the vagina of ovariectomized ewes.

A modified non-invasive vaginal probe, using electronic transducers to monitor six physical variables reflecting vaginal changes, was tested in oophorectomized ewes according to a Latin-Square design allocating six treatments to six animals in a balanced time sequence. The transducers measured thermal conductance, temperature near the cervix and near the vulva, and light reflectance at 900, 660, and 565 nm. The treatments included four iv doses of oestradiol-17 beta (0.5, 5.0, 50, and 500 microgram per 50 kg body weight) and two controls (injection vehicle, and no injection). Despite large residual variation, the results (1) show that the higher oestradiol doses produced responses of all six variables; (2) suggest improvements in future probe design; and (3) raise interesting questions on dose-response relationships deserving further study.