Gerhard Giebisch

Measurements of Electrical Potentials and Ion Fluxes on Single Renal Tubules

Experimental technics are described which permit the measurements of stable electrical potential differences across the cell membrane of single renal tubule cells and across single tubules. The inside of the tubule lumen is normally found to be electrically negative to the outside, while the cell interior is found to be negative to both the peritubular fluid and the tubule lumen. Such electrical measurements, in conjunction with known concentration gradients and flux measurements of various ions across single renal tubules, permit some deductions to be made on the driving forces involved in the movement of various ion species across the luminal and peritubular cell membrane of renal tubule cells.

Comparative Study of Uptake and Distribution of Hg203 Given as Labelled Chlormerodrin (Neohydrin).

Summary The uptake and distribution of Hg203 given as labelled chlormerodrin (Neohydrin) has been studied in the mudpuppy, carp, bullfrog, turtle, chicken and dog. Preferential binding of radiomercury by renal tissue was found in all animals with most tissue/plasma ratios of Hg203 well above one. For a given dose poikilothermic animals showed a slower accumulation and loss of radiomercury than did homoiothermic specimens. With the exception of the dog, in all animals there was only a slow fall in renal content of radiomercury over a time period of 46 to 70 hrs. In Necturus maximum mercury uptake was found in a part of the kidney made up predominantly of proximal tubules.