title: Electron microscopical tracers in the uterine epithelium of the pregnant guinea-pig.
abstract: Horseradish peroxidase and lanthanum nitrate were used in pregnant guinea-pigs as electron dense tracers to determine whether the 'permeability' characteristics of the uterine epithelium support the hypothesis that immunoglobulin G gains access to the uterine lumen by transepithelial diffusion. Horseradish peroxidase was injected intravenously in eight animals in experiments ranging from 1-43 min and directly into the uterine lumen in five animals in experiments of 1-8 min duration. Lanthanum nitrate was injected only into the uterine lumen of eight animals for exposures of 1-8 min. Horseradish peroxidase did not traverse the junctional complexes regardless of injection site; lanthanum nitrate did not penetrate the complexes either except in one animal. We conclude that the uterine epithelium is a barrier that prevents the diffusional transfer of IgG from mother to fetus. Further studies are required to locate the site where maternal IgG is transferred to the uterine lumen.
authors.affiliation: Department of Biology, Warner Pacific College, Portland, Oregon 97215.
authors.forename: D J
authors.initials: DJ
authors.lastname: Kimberly
authors.forename: K L
authors.initials: KL
authors.lastname: Thornburg
mesh_terms: D000818:Animals; D004058:Diffusion; D004848:Epithelium / Q000502:physiology / Q000648:ultrastructure; D005260:Female; D006168:Guinea Pigs; D006735:Horseradish Peroxidase / Q000493:pharmacokinetics*; D007074:Immunoglobulin G / Q000502:physiology; D007811:Lanthanum / Q000493:pharmacokinetics*; D008431:Maternal-Fetal Exchange / Q000502:physiology; D010544:Peroxidases / Q000493:pharmacokinetics*; D011247:Pregnancy; D014599:Uterus / Q000502:physiology / Q000648:ultrastructure*
chemical_list: D007074:Immunoglobulin G; C016534:lanthanide nitrate; D007811:Lanthanum; D006735:Horseradish Peroxidase; D010544:Peroxidases