Factors affecting the ultrafilterable fraction of o-iodohippurate in human plasma.

The ultrafilterable fraction (UF/P) of 131labeled o-iodohippurate (OIH) was measured in vitro and the effects of varying plasma OIH concentration (pOIH), plasma protein concentration (pPr) and plasma pH (ppH) determined. Dialysis coils were perfused with saline and human plasma at 38°C and pOIH varied (n = 46; pPr = 6.3–7.1 g/100 ml; ppH = 7.2–7.6), pPr varied (n = 126; pOIH = 50 mg/l00 ml; ppH = 7.2–7.6), or ppH varied (n = 121; pOIH = 84–106 mg/l00 ml). Ultrafiltrate was collected at different pOIH (10–90 mg/l00 ml), pPr (0–26 g/l00 ml), and ppH (5.7–9.8) values.Saline pPr constant pOIH constant