when rats were fed 6 % casein for 13 d and then fed the same 6 % casein diet with or without an additional 15 % ammonium acetate for an additional 7 d before feeding 75 % casein for 1 d , the plasma ammonia concentration of each group was not different , but plasma and brain amino acid concentrations were lower in rats prefed 15 % ammonium acetate before the 75 % casein diet .
C0006104
brain
C0086045
concentrations