X-ray microanalysis of uterine epithelial cells in culture

The ionic composition of the uterine fluid, secreted by the endometrium, is of importance for fertilization and embryonic development. Little, however, is known about the ion transport mechanisms in the uterine epithelial cells. Because it is difficult to study ion transport in this tissue in situ, a method was developed to culture mouse uterine epithelial cells for X-ray microanalysis in the electron microscope, in order to allow the study of ion transport. Our data suggest the presence of a number of ion transport mechanisms in the cultured uterine epithelial cells. The cells appear to possess a ouabain-sensitive Na⁺---K⁺-ATPase, an amiloride-sensitive Na⁺---H⁺ antiporter, cAMP- and Ca²⁺-activated chloride channels, and volume-activated chloride efflux and influx mechanisms. In addition, chloride efflux can be stimulated by cholinergic and alpha-adrenergic agonists. Only a few of these mechanisms had been studied previously in the uterine epithelium.     

Collection and X-ray microanalysis of airway surface liquid in the mouse using ion exchange beads

The airway surface liquid (ASL) is a thin layer of liquid covering the airway epithelium. The ionic composition of the ASL is assumed to be important for airway function and may be altered in diseases such as cystic fibrosis and exercise-induced asthma. A method for collection of ASL is presented in which the fluid is collected using small dextran ion-exchange beads. The beads are equilibrated with the ASL in a humidity chamber, collected under silicon oil, dried and analyzed by X-ray microanalysis. Analysis of standard beads prepared by exposure to different salt solutions shows that linear calibration lines can be obtained, but that beads absorb different elements to a different extent. The results show that the ASL in mice is hypotonic, and that the mucus component of the ASL has an elemental composition that is different from that of the periciliary fluid.     

Association of Molybdenum Ionic Species with Alumina Surface

The adsorption isotherms at 25, 45, and 65 degrees C of molybdenum solutions of concentration ranges between 10(-3) and 3x10(-2) M(Mo) (pH 4-5) on different alumina samples are investigated. The analysis is conducted using a modified Frumkin isotherm which takes a more realistic account of the lateral interaction between adsorbed species and considers that the adsorption takes place on the most basic OH groups on the surface of alumina. The results are discussed in view of the difference in solutions speciation, and the changes in the pH of the remaining supernatant solutions. The solution temperature, PZC of the used aluminas, the configuration of the basic OH groups on their surface, and the pore structure have been shown to intervene effectively. Copyright 2000 Academic Press.