Evaluation of danazol influence upon the uterus using scanning electron microscopic morphometric and biochemical analyses.

A study using a Sprague-Dawley rat model was designed to correlate morphologic and intracellular steroid receptor alteration with danazol therapy. One uterine horn was removed for cytoplasmic estrogen receptor analysis following four to eight days of danazol therapy. This was followed by intra-aortic injection of buffered phosphate solution and 3 per cent glutaraldehyde. The remaining uterine horn was removed for scanning electron microscopic and morphometric analysis of light microscopic changes. After four days of treatment, there was an increase in the nuclear to cytoplasmic ratio compared with that of the control tissue. Vaginal smears on the eighth day of danazol exposure indicated that the rats had entered a noncycling estrus state, and there was a significant increase in the estrogen-specific binding capacity of the endometrial cells. Scanning electron microscopy showed a distinct decrease in endometrial folds, microvilli and glandular openings, which suggests a decline in secretory activity in the danazol-treated group. Thus, danazol induced measurable changes in the estrogen binding capacity of endometrial cells, and these changes correlated with certain morphologic alterations in the endometrial lining.