The diurnal variation in renal iodide excretion rate in rabbits.
The diurnal variation in renal iodide excretion rate was determined in unrestrained female rabbits by means of either a conventional clearance technique or a continuous monitoring of the whole body disappearance of iv injected 125I-iodide using an implanted Geiger-Muller detector. A distinct diurnal rhythm was detected in the disappearance rate of 125I-iodide. A slow disappearance rate occurred from 12 p.m. to 6 a.m. (darkness from 5 p.m. to 5 a.m.). The values of iodide excretion rate obtained by both methods were consistent like in humans with an excretion fraction of 0.3 for iodide in rabbits. In rabbits weighing 3-4 kg the renal iodide excretion rates were 5-7 ml/min during the rapid phase and 3-4 ml/min during the slow phase.
D000818:Animals; D002940:Circadian Rhythm; D005260:Female; D007668:Kidney / Q000378:metabolism*; D011817:Rabbits; D013686:Telemetry