1. The metabolism of glycerol by isolated rat-kidney tubules was investigated.
2. Indomethacin, at a concentration of 0.1 mmol/l, markedly inhibited the utilization of glycerol and its conversion into glucose and CO2.
3. The glycerol 3-phosphate production rose significantly when indomethacin was present, indicating a fall in the rate at which glycerol 3-phosphate was oxidized.
4. The results are discussed in relation to the observation that indomethacin increases the severity of glycerol-induced acute renal failure.