Table 4 Influx and net flux of amino acids in the indicated species
Rat1 Rat2 Rat3 Rat4 Rat5 Rat6 Dog7 Dog7 Cat8 Sheep9 Human10 Human11 Human12 Human13 Human14
Influx* Influx Influx Influx Influx Net Net* Net* Net Net Net Net Net Net Net
Phenylalanine 6.5 7 8 13.2 − 0.6 0.12 0.01 2.2 0.06 0.3 − 0.5
Leucine 6.2 15 14.5  9.7 1.56 1.28 1.9 6 5.2 3.2 2.2 0.6
Isoleucine 1.8 4  5.7 0.78 0.46 1.5 3.1 1.2 1.4 0.7 0.3
Valine 1.3 1.8  2.9 1.26 0.37 2.7 11.0 1.7 0.8 − 1.7
Tyrosine 5.3 7 4.1 − 1.1 0 0.06 1.6 0.1 − 0.1 − 0.1
Methionine 1.6 1.7 − 1.1 0 − 0.12 1.0 0.6 0.2 0.2
Tryptophan − 1.1
Histidine 2.5 2.5 − 1.7 − 0.23 − 0.7 0.7 − 0.3 − 1.3
threonine 1.2 0.8 − 3.4 0.62 − 0.1 5.0 2.6 0.1
Arginine 1 − 7.4 − 0.2 − 0.05 2 0.7 − 0.5 − 0.1
Lysine 6.2 9 − 1.1 0.58 − 1.6 2.5 − 0.3 − 0.9
Glutamate  1.7 − 0.24 − 0.18 − 0.05 1.4 − 0.5 − 6
Glutaminea 11.6 1 − 15.4 − 6.6 − 4.3 − 1.94 − 7.4 11.0 − 20 − 20.4
nerv. stim.b glutamate − 1.26
nerv. stim.b glutamine − 6.69
Values are stated in nmol g−1 min−1. Influxes have been measured only in rats. The only available measurements of net fluxes in rats, shown in the italicized column, failed to reach statistical significance
* Data used by Pardridge [379] in his comparison of influxes and net fluxes
aIn some columns the values are for glutamine + asparagine as the assay used detected both
bRelease measured during nervous stimulation
1Banos et al. [369]
2Hawkins et al. [583]
3Mans et al. [584]
4Ennis et al. [415]
5Smith and Stoll [43]
6Brosnan et al. [378]
7Betz and Gilboe [365]
8Abdul-Ghani et al. [394]
9Pell and Bergman [585]
10Felig et al. [586]
11Lying-Tunell et al. [587]
12Eriksson et al. [588]
13Grill et al. [589]
14Strauss et al. [590]