Effect of treatment with GHB alone or GHB with L-lactate, GHB with D-mannitol, or GHB with the combination of D-mannitol/L-lactate on urine pH and volume. Urine pH changes (A) and urine volume changes (B) after administration of 60.5 mg h−1 kg−1 L-lactate, 0.5 g/kg D-mannitol, and the combination of D-mannitol and L-lactate. One-way ANOVA followed by Dunnett's test, n = 3 to 5, mean ± S.D. *, p < 0.05; **, p < 0.01.