Scanning electron microscopy of the responses of postmenopausal endometrium to treatment with estriol and estriolprogesterone.

Seven postmenopausal women are given estriol orally in a daily dose of 1 mg x 2 or 5 mg x 2 for 14 or 28 days and 2 women were sequentially treated with 5 mg x 2 of estriol orally for 21 days, with the addition of 0.2 g x 2 of progesterone rectally in the last 7 days. Three women served as controls. Scanning electron microscopy revealed that the former treatment with estriol was sufficient to produce an estrogen response in the non-ciliated uterine epithelial cells, which developed many long microvilli, sometimes arranged in tufts. The sequential treatment with initial estriol priming followed by estriol and progesterone combined resulted in a slight secretory transformation of the uterine epithelium, observed as an increase in size and number of the apical protrusions of the cells.