Histological changes induced by tamoxifen versus tamoxifen plus 13-cis-retinoic acid on rabbit uterine glands.

OBJECTIVE To study the effects of tamoxifen versus tamoxifen plus 13-cis-retinoic acid on the histology of uterine glands in rabbits. METHODS The experimental, randomised, controlled trial was conducted at the Army Medical College, Rawalpindi, from March 2009 to June 2009 and comprised rabbits acquired from the National Institute of Health, Islamabad. The animals were randomly divided into three equal groups: group A had controls, group B was treated with tamoxifen, and group C with tamoxifen plus retinoic acid. The uterine weight and cross-sectional diameter of uterine horns were measured after sacrifice. The uteri were processed for paraffin embedding. The sections were then assessed for stratification of glandular epithelium, changes in the glandular shape and glandular epithelial height. SPSS 13 was used for statistical analysis. RESULTS Tamoxifen administration resulted in variation of glandular shape and increase in glandular epithelial height in group B as compared to control group, p < 0.001 and 0.005 respectively. The adjuvant administration of 13-cis-retinoic acid showed a suppressive effect only on glandular epithelial height, when compared with Group B (p=0.01). CONCLUSIONS The 13-cis-retinoic acid has no significant inhibitory effect on uterine glandular proliferation induced by tamoxifen after a short-term administration of three months.