at the optimal ph ( 4.5 ) , active uptake of carrier-free [ ( 14 ) c ] citrate in 50 micromolar mersalyl is inhibited by fourteen anions , but only the i ( 50 ) ( the concentration of inhibitor required to reduce uptake of carrier-free [ ( 14 ) c ] citrate by 50 % ) values of citrate ( 0.08 millimolar ) and d-and l-isocitrate ( 0.5 millimolar ) are less than 4 millimolar .
C0003075
anions
C0021966
i