A microprobe study of element distribution in vaginal epithelial cells of the rat

Microprobe analysis of vaginal epithelial cells shed during the estrous cycle of the rat was done to determine cellular elements present in successive stages: pro-estrus, estrus, and post-estrus. Smears of vaginal contents were placed on carbon planchettes, fixed by freeze-drying, and examined in a scanning microscope with an energy dispersive spectrometer. Concentrations of Na, Mg, P, S, Cl, K, and Ca were calculated (mmol/kg dry weight) and analyzed statistically. For phosphorus a significant fall at estrus correlates with a loss of nuclear and cytoplasmic nucleic acids and nucleoproteins. An increase in sulfur at estrus is consistent with an accumulation of keratins over pro-estrus and a greater increase over the post-estrus epithelial cells. The epithelial cells of pro-estrus are highest in Mg and Ca. By post-estrus, the cells have recovered their Mg, not Ca. Potassium concentrations exhibited no significant change between the successive stages.