ALTERATIONS IN SULFOBROMOPHTHALEIN SODIUM-REMOVAL MECHANISMS FROM BLOOD DURING NORMAL PREGNANCY*

Abstract

Hepatic sulfobromo-phthalein sodium (BSP) removal mechanisms have been appraised quantitatively during pregnancy and the 1st week postpartum in terms of (1) the relative storage capacity for BSP,S, defined as the number of milligrams of dye taken up into storage for each increment of plasma concentration of 1 mg/100 ml and (2) the maximal excretory rate of BSP into bile, BSP Tm, in milligrams per minute. S rose 122% during the last half of pregnancy, then returned to or toward normal during the 1st week postpartum. By contrast, BSP Tm decreased 27% in the last half of pregnancy, then rapidly increased to normal levels after delivery. These changes appear to reflect alterations in 2 independent hepatic mechanisms.