Renal metabolism of homologous serum interferon

The metabolic behaviour of homologous native and desialylated serum and urinary interferons has been investigated by using an isolated and perfused rabbit kidney, the performance of which is comparable to that in vivo. Serum native and urinary interferons disappear from the plasma perfusate with a fractional turnover rate of 1.8 and 2% and half-lives of 3 and 35 min, respectively. Serum desialylated interferon disappears much more rapidly in keeping with the finding that the glomerular sieve poses less steric hindrance and electrophysical repulsion to the passage of less anionic proteins. These results confirm and extend our previous findings, which indicated that the kidneys have a predominant catabolic role and can explain to some extent the rapid disappearance of interferon from plasma.