Simultaneous comparison of techniques for x-ray analysis of proximal tubule cells.

Major differences in elemental and water content in cells of rat papillae in antidiuresis have been reported using x-ray microanalysis. The reason for these reported differences in unknown. In order to determine if the differing microprobe techniques used in these reports could account for the differences measured, we analyzed elemental concentrations in rat proximal tubule cells using both methods simultaneously on the same cells. Both methods provided comparable results. Furthermore, no differences in element or water content of proximal tubule cells cryosectioned with albumin at -53 degrees C and those cells cryosectioned at -80 degrees C were seen. Therefore, the differing values previously reported for elemental analysis of rat kidney cannot be ascribed to either cryosectioning at a warmer temperature or to the analytical algorithm used by either group.