CONCENTRATION OF LISSAMINE GREEN IN PROXIMAL TUBULES OF ANTIDIURETIC AND MERCURY POISONED RATS AND PERMEABILITY OF THESE TUBULES

By coloring castor oil with Sudan-red we were able to modify the split droplet method so that concentrations of Lissamine green (LG) could be determined by microphotometry in individual proximal tubular loops of rat kidneys. In the course of the split droplet experiments an increase in the concentration of LG occured, which corresponded to the decrease in volume of the solvent (calculated from the intratubular diameter and the length of the test droplet) only with test lengths of over 100 μ. The change in concentration at shorter lengths of test droplets may have resulted from an incomplete blockage between the oil block and the test droplet. The modified split droplet method was applied to determine tubular permeability after mercury poisoning. In contrast to the control experiment, the test droplet stained with LG became decolorized during the split droplet experiments, a change which in small part may have been caused by the binding of LG with protein to form an uncolored compound. The protein resulted by the damage of the tubular cells after mercury poisoning. Furthermore, a considerable increase in the permeability of the proximal tubular wall must have occured, since we could show in microperfusion experiments that proximally injected C14-labelled Inulin was excreted in large quantities through the other (unpunctured) kidney after mercury poisoning. © 1969 Springer-Verlag.