Morphology of the apical surface of endometrium on 1st, 6th and 22nd days of pregnancy in rats [Transmission and scanning electron microscopic study]

ABSTRACT

Morphology of the apical surface of the luminal epithelial cells of the endometrium of the rats on the 1st, 6th and 22nd days of pregnancy was examined by transmission and scanning electron microscopes. Twenty adult female and five adult male rats were used in this study. The animals were subsequently euthanized on either the 1st, 6th and 22nd days of pregnancy [term=23 days]. Using transmission electron microscope, the microvilli covering the apical surface of the luminal epithelial cells were long and irregularly spaced on the 1st day of pregnancy. They became shorter in length, numerous fewer in number and showed pinopods on the 6th day of pregnancy. Finally, they became numerous, long and slender on the 22nd day of pregnancy. Using the scanning electron microscope, it was observed that the uterine luminal epithelium was covered with long and slender microvilli on the 1st day of pregnancy. As pregnancy advanced, they became shorter and sparsely distributed with the presence of membranous protrusions on the 6th day of pregnancy. Late in pregnancy, on the 22nd day, the microvilli became longer and more numerous but no membranous protrusions could be observed