FREE AMINO ACIDS OF BLOOD AND URINE 243 
lets?®. The free amino acid content of plasma, erythrocytes, leucocytes and platelets 
is currently under investigation in our department by means of automatic ion- 
exchange chromatography. The data already collected by SOUPART AND SCHRAM 
(unpublished) draw attention to sone problems that arise from methods used 
for single species cell preparations in view of amino acid analysis. Results of a typical 
analysis of formed elements prepared as described in MATERIAL AND METHODS, are 
presented in Table VII, and graphically shown in Fig. 8. As can be seen, free amino 
acid concentrations differ considerably in the four compartments of the blood 
pm / 100 mt ye 


900 900 
P{ 2100 
800 4 + 800 
| 
é a 
llgqg ¥ 
ol +600 
id b 500 
asl +400 
* 
300 n +300 
2007 +200 
100 4 + 10¢ 
| 
= Y 3 
: - Va a | ] : 
43. il A | AJ a - of ia on or me 3 nis = ms z 
Tau Lys Gly a-Ala val Leu Ileu Ser Thr Phe Tyr His Arg Asp Glu Met \ycys Pro 
Fig. 8. Free amino acid concentration in plasma (I), erythrocytes (II, the lower part of each bar 
indicates what is left after diffusion losses, see text), leucocytes (III), platelets (IV) and urine 
(V). Glutamic acid (*) is present in freshly voided urine only in the form of glutamine. 
reservoir, except those of erythrocytes in which the concentrations of a majority of 
amino acids are similar to those found in the plasma. It is also to be noticed that 
when blood cells are separated by such a method as the one used in this experiment, 
some amino acids are allowed to diffuse out of the erythrocytes, which does not seem 
to be the case with leucocytes and platelets, or at least not to the same degree. 
Differences in concentration may be appreciated by expressing individual amino 
acid concentration relatively to that found in the plasma taken as unity. This has 
been done in Table VIII, which emphasizes the following facts: 
a) Leucocytes. Free amino acid concentrations are the highest in this reservoir. 
Of special interest is the case of taurine which is several hundred times more con- 
References p. 261/262 
