Pharmacokinetic studies of oxalate in man

The observation of the plasma concentrations after rapid intravenous administration of inulin and 14C-oxalate to six normal and one hyperoxaluric subjects allowed estimations of the half-life of elimination of oxalate (mean 91.7 min), volume of distribution of oxalate (mean = 32.5 liters), calculation of the miscible oxalate pool (mean 3.7 mg), of the plasma oxalate concentration (mean = 11.1 microgram per 100 ml), of the oxalate clearance (252 ml per min), and the determination of the oxalate turnover rate (0.027 mg per min). The 14C-oxalate/inulin clearance ratio was 2.44 implying an additional excretion mechanism apart from glomerular filtration. Inasmuch as 97.2 per cent of the administered tracer were recovered unchanged in urine, nonrenal loss of oxalate is not an appreciable factor. The data of one hyperoxaluric patient are compared with those of the healthy subjects.