Temporal variations in the elimination of antipyrine in normal and adrenalectomized rats.

An oral dose of antipyrine was administered at 08:00 and 20:00 hours to groups of sham operated and adrenalectomized rats standardized in an alternating 12-hour-light-dark cycle for 7 days prior the experiments. Temporal variations in the rate of elimination of antipyrine were obtained in both groups. Adrenalectomy decreased the serum elimination of antipyrine but had no effect on the temporal variations.