title: Intestinal uptake of fluorescent microspheres in young and aged mice.
abstract: Rhodamine B-labeled synthetic latex particles (microspheres), 1.8 micron in diameter, were administered by gavage 5 days per week to young (24 days) and aged (18 months) mice. After 25 days (19 gavages), the particles were assayed in solubilized tissues by depositing them on filters and counting under fluorescence microscopy. Aged mice exhibited significantly more fluorescent particle accumulation in Peyer's patches but significantly less in lungs than young mice. Mesenteric lymph nodes and Peyer's patch-free intestinal segments contained measurable latex, but differences between young and aged animals were not significant. Liver contained only trace amounts of latex, and spleen and kidney were latex free in both young and aged animals. Nonquantitative observations on KOH-glycerol-cleared whole Peyer's patches and slices of liver, lung, and mesenteric lymph node were similar.
authors.affiliation: Medical Research Center, Brookhaven National Laboratory, Upton, New York 11973.
authors.forename: M E
authors.initials: ME
authors.lastname: LeFevre
authors.forename: A M
authors.initials: AM
authors.lastname: Boccio
authors.forename: D D
authors.initials: DD
authors.lastname: Joel
mesh_terms: D000375:Aging / Q000502:physiology*; D000818:Animals; D005260:Female; D005456:Fluorescent Dyes; D007408:Intestinal Absorption; D051379:Mice; D008856:Microscopy, Fluorescence / Q000379:methods; D008863:Microspheres; D012235:Rhodamines; D014018:Tissue Distribution; D014966:Xanthenes
chemical_list: D005456:Fluorescent Dyes; D012235:Rhodamines; D014966:Xanthenes; C029773:rhodamine B