Relation of potassium to urate accumulation by kidney slices from desert spiny lizards (Sceloporus magister)

1. 1. The relation of medium potassium concentration to urate accumulation by kidney slices from desert spiny lizards (Sceloporus magister) was studied. 2. 2. Incubation in 40 mM potassium caused a marked increase in urate accumulation. Preparation and incubation in potassium-free medium depressed, but did not eliminate, active urate accumulation. 3. 3. Incubation of potassium-depleted slices in media of increasing potassium concentration restored tissue potassium when medium potassium reached 40 mM but did not completely restore urate accumulation. 4. 4. These data suggest that severe depletion of potassium impairs mechanisms for both potassium and urate accumulation, and that the latter is not restored even when tissue potassium is restored. 5. 5. These results differ from those observed previously with kidney slices from domestic fowl and ophidian reptiles. Differences may be related to the membrane site of transport.