Itsuro Tamanoi

CHANGES OF BLOOD PLASMA ELEMENT CONTENTS IN X-RAY IRRADIATED MICE BY PIXE ANALYSIS

The quantitative changes of elements in blood plasma were observed with the passage of time after X-ray whole body irradiation with 12 Gy on C57BL/6J mice by PIXE method. From 4 days after irradiation, dead mouse was found and all mice died by 8 days. Hematocrit (Ht) values indicated a decrease from the 1st day, but on days 3 and 4 there was a small rise. Finally the values became 64 % of that of non-irradiated control on day 7, it was just before death. By analysis with PIXE method, 15 elements were observable in blood plasma of control mice. The elements such as P, S, Cl, K, Ca and Cr were abundant and Fe and Br followed. As trace elements, the peaks of Zn, Cu and Ni were clearly observed. After irradiation, K and Ca decreased on day 1st, afterwards increased gradually. On the contrary, the elements, S, Cl, were rather stable. While Fe decreased from 1st day, Cu increased from the day 2. Zn and Ni showed intensely down and rise in amount, and decreased on day 7. The results of possible measurement of the changes in amount of these elements of blood plasma suggest PIXE method is an easy and useful way for diagnosis.

PIXE STUDIES ON POTASSIUM AND CALCIUM IN MOUSE BLOOD PLASMA AFTER TRANSPLANTATION OF EL-4 TUMOR CELLS

The quantitative changes in the elements, amounts of Cl, K, Ca, in blood plasma were measured by PIXE method. The samples were obtained at appropriate intervals after transplantation of EL-4 tumor cells in three strains of mice, C57BL/6J (H-2b), C57BL/10J (abbreviation: B10; H-2b) and A/J (H-2a). Transplanted EL-4 tumor cells proliferated in both strains of C57BL/6J and B10. In A/J mice, transplanted EL-4 cells proliferated about 10 days and then were rejected completely by the immunological reaction according to the difference of major histocompatibility antigens. The amounts of Cl in plasma remained at similar level in the time course in any strains, but K fluctuated in C57BL/6J and B10, and less in A/J. On the other hand, Ca showed always higher values in C57BL/6J than other two strains of mice. In B10 mice, Ca increased just before death, but in A/J it decreased at the time of healing by rejection. These changes of Ca in the three strains of mice were related quantitatively 10 the hematocrit values of these strains of mice after transplantation of EL-4 cells.

POSSIBLE APPLICATION OF PIXE METHOD TO INTESTINAL PERMEABILITY MEASUREMENT

We measured intestinal permeability of mice by PIXE method. A mixture of a rubidium chloride solution and a manganese chloride solution was administered orally into mice. The blood was sampled successively after the administration, and the element contents in the blood were measured by PIXE method. The Rb content in the plasma of Rb+Mn administered group reaches maximum 5 min after the administration and decreases subsequently. The value in the whole blood of Rb+Mn administered group increases slightly for first 30 min after the administration and remarkably from 3 hrs. This increase continues for 48 hrs. That in control group is very little. Rb is probably transferred into plasma from intestinal mucosa at first, and subsequently moves into blood cells. The Mn content in control group is little. The values in the whole blood and the plasma of Rb+Mn administered group reach maximum 5 min after the administration and then decrease, and turn to decline to control level at 24 hrs. Mn is probably transferred into blood from intestinal mucosa throughout, and washed out more rapidly than Rb. The element contents of Rb and Mn in the plasma of Rb+Mn administered mice are found to increase to the peak level 5 min after the administration. Rb and Mn are useful as a tracer to study of intestinal disease with measurement by PIXE method. With this manner by PIXE method, intestinal permeability can be measured more briefly than existing methods. In order to assess intestinal permeability, we propose an indicator which is obtained by comparing the element amounts of Rb and/or Mn in blood sampled just after the administration.

Use of rubidium, manganese, and zinc as tracers to measure intestinal permeability by PIXE analysis: basal study in an experimental enteritis model.

Intestinal permeability has been suggested to be closely linked with the etiology or activity of Crohn’s disease. However, current methods for measurement of intestinal permeability are too laborious for routine examination, as they require urine collection and/or use of radioisotopes. The present study was performed to develop a more convenient and safer method for assessing intestinal permeability using blood samples rather than urine. Rats with indomethacin-induced enteritis were orally administered Rb, Mn, and Zn as tracers. Intestinal permeability was determined by assaying the levels of Rb, Mn, and Zn in blood samples by particle-induced X-ray emission (PIXE). The distributions of Rb, Mn, and Zn in the small intestine after administration were analyzed by micro-PIXE. The conventional PIXE analysis showed that the levels of Rb and Zn in the blood in the enteritis group were correlated with the grade of enteritis. The micro-PIXE analysis showed that Rb, Mn, and Zn were translocated into the wall of the proximal small intestine 5 min after administration, and this effect was more conspicuous in the enteritis group than in controls. Analysis of blood or small intestine tissue samples using the PIXE allows determination of both intestinal permeability and the route of permeation.