Table 2. Na⁺- and Cl⁻-dependence and inhibitory effect of several compounds on [¹⁴C]GAA uptake by freshly isolated rat hepatocytes.

Conditions/Inhibitors	% of control
Na+- and Cl—dependence
Control	100±12
Na+-free	35.6±2.5*
Cl—free	40.3±1.6*
Inhibitory effect
Control	100±4
Guanidinoacetic acid (GAA)	24.1±1.1*
GABA	17.1±1.6*
β-Alanine	28.5±5.5*
β-Guanidinopropionic acid	18.9±0.9*
Guanidinoethansulfonic acid	33.0±4.4*
Nipecotic acid	30.8±1.2*
Creatinine	75.3±8.9**
Guanidinosuccinic acid	71.2±5.1*
Betaine	64.4±8.7*
L-Arginine	74.9±11.1*
Glycine	54.4±11.2*
L-Alanine	59.6±7.8*
L-Serine	83.8±6.4

[¹⁴C]GAA (18 µM) uptake by hepetocytes was measured at 37°C for 3 min in the absence or presence (control) of Na⁺ and Cl⁻ or in the absence (control) or presence of inhibitors (2 mM). Each value represents the mean±SEM (n = 3–4).

*p<0.01,

**p<0.05, significantly different from the control.