Histology of the vaginal epithelium of the sow during oral administration of methallibure (ICI 33828).

Abstract

<section class="abstract"><h2 class="abstractTitle text-title my-1" id="d405109e2">Summary.</h2> Serial vaginal biopsies were taken from sows receiving 100 or 150 mg methallibure daily (Groups 1 and 2), from untreated pregnant sows following mating (Group 3) and from untreated, unmated sows (Group 4). Group 1 received methallibure from the 2nd day of oestrus (Day 0) for 30 days and Group 2 received similar treatment for 20 days from Day 11 of the cycle. The biopsies were examined histologically for their general character and the number of epithelial cell layers was recorded. During Days 9 to 14 (di-oestrous period), there were no significant differences between the number of epithelial cell layers in the four groups. During Days 19 to 24 (oestrous period), there were no significant differences between Groups 1, 2 and 3 but all these groups were significantly different from Group 4 (<em>P</em>&lt; 0·001). The values on individual days in the oestrous period in Groups 1, 2 and 3 were also significantly different from Group 4 (<em>P</em>&lt;0·01). The findings are discussed in relation to the mode of action of methallibure and to the vaginal biopsy method of pregnancy diagnosis in pigs. </section>