Table 1.
Brain amino acid composition after chronic treatment with α-methylphenylalanine or α-methylphenylalanine plus phenylalanine for 10 or 16 days
| Amino acid | Controls (μmol/g brain) | αMePhe (% control) | αMePhe+Phe (% control) | |||
|---|---|---|---|---|---|---|
| 10 days (n=4) | 16 days (n=3) | 10 days (n=3) | 16 days (n=1) | 10 days (n=7) | 16 days (n=4) | |
| Phosphoserine | 0.14 ± 0.02 | 0.09 ± 0.01 | 77 ± 11 | 157 | 79 ± 14* | 100 ± 29 |
| Glycerolphospho-ethanolamine | 0.27 ± 0.02 | 0.13 ± 0.02 | 101 ± 23 | 134 | 89 ± 17 | 136 ± 24 |
| Phospho-ethanolamine | 5.99 ± 0.22 | 2.70 ± 0.06 | 64 ± 3* | 133 | 79 ± 20 | 124 ± 9 |
| Taurine | 15.4 ± 1.6 | 9.30 ± 1.56 | 98 ± 11 | 121 | 98 ± 15 | 150 ± 27* |
| Aspartate | 2.13 ± 0.12 | 1.94 ± 0.25 | 91 ± 13 | 79 | 90 ± 14 | 184 ± 24** |
| Threonine | 0.70 ± 0.02 | 0.53 ± 0.08 | 119 ± 10 | 73 | 107 ± 13 | 167 ± 43 |
| Serine | 1.15 ± 0.06 | 1.08 ± 0.15 | 89 ± 19 | 75 | 91 ± 13 | 95 ± 5 |
| Glutamine | 3.13 ± 0.32 | 2.77 ± 0.61 | 78 ± 18 | 97 | 86 ± 12 | 114 ± 20 |
| Glutamate | 6.75 ± 0.43 | 6.51 ± 1.62 | 80 ± 19 | 97 | 81 ± 15* | 123 ± 5 |
| Glycine | 0.80 ± 0.11 | 0.49 ± 0.06 | 152 ± 38* | 86 | 202 ± 55** | 304 ± 48*** |
| Alanine | 0.62 ± 0.07 | 0.65 ± 0.17 | 82 ± 22 | 63 | 71 ± 8** | 88 ± 20 |
| Valine | 0.94 ± 0.01 | 0.08 ± 0.01 | 122 ± 13 | 227 | 53 ± 24** | 71 ± 41 |
| Cystathionine | 0.13 ± 0.02 | 0.09 ± 0.07 | 122 ± 19 | 143 | 104 ± 21 | 92 ± 13 |
| Methionine | 0.07 ± 0.02 | 0.40 ± 0.00 | 71 ± 9 | 123 | 56 ± 7* | 73 ± 10** |
| Isoleucine | 0.08 ± 0.01 | 0.10 ± 0.01 | 59 ± 11** | 68 | 50 ± 10* | 52 ± 24 |
| Leucine | 0.13 ± 0.02 | 0.17 ± 0.04 | 121 ± 10 | 60 | 58 ± 13* | 38 ± 15** |
| Tyrosine | 0.14 ± 0.02 | 0.13 ± 0.04 | 99 ± 33 | 85 | 179 ± 45** | 204 ± 106 |
| Phenylalanine | 0.05 ± 0.00 | 0.05 ± 0.00 | 432 ± 143* | 442 | 3359 ± 992* | 3717 ± 2772 |
| GABA | 1.12 ± 0.13 | 1.36 ± 0.26 | 104 | 89 | 97 ± 8 | 119 ± 10 |
| Ornithine | 0.05 ± 0.01 | -- | 141 | -- | 113 ± 39 | -- |
| Ethanolamine | 0.16 ± 0.02 | 0.14 ± 0.03 | 88 | 79 | 111 ± 47 | 143 ± 74 |
| Lysine | 0.24 ± 0.05 | 0.25 ± 0.03 | 101 | 110 | 87 ± 13 | 117 ± 19 |
| Histidine | 0.12 ± 0.01 | 0.12 ± 0.03 | 96 | 79 | 84 ± 21 | 116 ± 22 |
| Arginine | 0.10 ± 0.03 | 0.10 ± 0.01 | 88 | 75 | 86 ± 8 | 119 ± 22 |
Values are means ± SD for the indicated number (n) of pooled brain samples, each of which was comprised of 4–6 brains
P<0.05
P<0.01 vs. same-age control.
Dashes indicate not measured. Rats were injected once daily with α-methylphenylalanine (αMePhe) or α-MePhe + Phe from age 3–16 days. The Phe dose was 5.2 μmol/g from 3–10 days and it was doubled to 10.4 μmol/g from 11–16 days to account for faster Phe clearance. Samples were obtained at 12h after the last injection of αMePhe at 10 and 16 days, at 2.5, 6, 9, 12, 15h after the injection of αMePhe+Phe at 10 days (tabulated values are means of all time points), and at 6 and 12h after the injection at 16 days (values are means of both time points).