245 P. SOUPART 
Leucocytes. Although no distinction can be made here between the different 
varieties of white blood cells, it appears that leucocytes as a whole contain about 
ten times more free amino acids than the plasma compartment, although the latter 
has a volume 50 times greater than that occupied by the circulating leucocytes 
under normal conditions. Taurine, aspartic acid and glutamic acid content is remerk- 
able in this respect. 
Platelets. Although half the volume of the circulating leucocytes this compart- 
ment has a very high content in free amino acids. 
Erythrocytes. When non-washed red cells are considered it may be seen that its 
capacity is lower than that of the plasma with regard to taurine, lysine, alanine, 
isoleucine, serine, phenylalanine, tyrosine, methionine, cystine and proline; higher 
than that of plasma as regard to glycine, leucine, histidine, aspartic and glutamic 
acids (especially the latter two); and about the same as plasma as regard to valine 
and threonine. 
When considering all the above data, it must be borne in mind that it is only an 
approximate evaluation, bound to several limitations, namely the method of prep- 
aration of the formed elements which has been used, the fact that the phenomenon 
described reflects complex situations, depending upon continuing intrinsic metab- 
olism during the separation process which requires at least several hours to be 
completed, and also depending upon secondary factors, such as volume contraction, 
which might be involved in in vitro experiments. 
AMINOACIDURIA IN VARIOUS CONDITIONS 
Since a general review on aminoaciduria has been published by BiGwoop e¢ al.} 
giving a complete and detailed account of the literature up to August 1958, some 
new knowledge has been gained which leads to reconsideration of the classification 
of types of aminoaciduria in diseases!*. This section is devoted to data recently col- 
lected with regard to aminoaciduria in various conditions in man: the problem of 
“b-aminoisobutyric acid excreters”, the free amino acid excretion in protein malnu- 
trition and some observations on the effects of X-irradiation on free amino acids of 
blood plasma and urine in certain types of malignant diseases. By way of con- 
clusion a provisional classification of hyperaminoaciduria in diseases will be sub- 
mitted. 
fb-aminoisobutyric acid excreters 
As shown in Table I, 6-aminoisobutyric acid (BAIBA) is excreted in rather small 
amounts by healthy adults: from o-52 mg/day, in the average 26 mg/24h (or 
0-500 wmoles, average 252 wmoles/24 h). This excretion range has been found in a 
group of 24 white adult subjects and the individual values were uniformly dis- 
tributed among the excretion range. 
In the child, up to 2 years old, BAIBA excretion was found to vary between 
o and 12 mg/24 hin a group of ten young white normal subjects. “BAIBA excreters” 
have been so called after a study done by Harris in 1953 (ref. 53) in a group of 345 
healthy white people of the British Isles. HArrIs found that approx. 10% of the 
subjects investigated excreted abnormally large amounts of BAIBA, and he con- 
References p. 261/262 
