CAPILLARY PATENCY AND PERMEABILITY IN THE ENDOMETRIUM SURROUNDING THE IMPLANTING RAT BLASTOCYST

Abstract

The patency and permeability of the endometrial vasculature surrounding the implanting rat blastocyst on day six of pregnancy were investigated using vascular corrosion casting/scanning electron microscopy (SEM), light microscopy, transmission electron microscopy and the intravascular (i.v.) injection of Evans' blue dye and fluorescein isothiocyanate (FITC) tagged albumin. Vascular casting revealed an absence of subepithelial endometrial capillaries at the centre of the implantation site resulting in an ovoid space in the casts averaging approximately 420 microns long by 210 microns in diameter. Fluorescent microscope observations on sections of implantation sites cut after an i.v. injection..