FREE AMINO ACIDS OF BLOOD AND URINE 251 
its excretion during the control period. The excretion of this amino acid rises up to 
four times the control value. The arrows indicate the time of X-irradiations. 
Fig. 10 shows the free and combined taurine excretion pattern after irradiation, 
The excretion of the free, as well as that of the combined form, immediately after 
the first irradiation, rises up to ten times the control values, and this is more than 
twice the highest value recorded in the normal up to now. But subsequent irradia- 
tions seem to be less active on taurine excretion. 
This increased urinary excretion of both taurine and BAIBA is attributable to 
plasma overloading, since plasma levels of these amino acids are significantly raised 

Taurine 
mg /24h BS BS 
*] | | CJ Free Taurine 
| ia Combined Taurine 
; | X-Ray doses: 50R 
f-Aminoisobutyric Acid 400 2, SeSpieciares 
X-Ray doses: 50R 2 Rin Stes 
75 ying /2sn S: Spleen area . AULD lee 
| ae S BS: Blood sampling 
é LN:Lymph nodes a 
so g 
2 [ | 300 4 iw 
xo [ | g 
las 5 
50 ws ie 
z [ | | . 
5 200 | 













5 
ns 2 









y 
25 BS 
1004 ll 
| 
OM RISE OM CRTAR GMO! 10819 ( tok ER ihe 
+4 gt? 2.3456 7 8 9 1011 
Se S LN S LN vl feet k 
3° Ss S LN S LN 
Fig. 9. B-Aminoisobutyric acid excretion in a Fig. ro. Free and combined taurine excretion 
chronic lymphocytic leukemic patient after the- in a chronic lymphocytic leukemic patient 
rapeutic X-irradiation (0, control excretion). after therapeutic X-irradiation (0, control 
excretion). 
shortly after irradiation. Increased renal function (7.e. increased glomerular filtration 
rate, for instance) and/or lowering of renal tubular reabsorption do not seem to 
be involved in this particular case, since none of the other amino acids is excreted 
in higher amount than usual. 
BAIBA is known to be released in abnormally high amount as a result of cell 
breakdown initiated by X-irradiation. This amino acid is in fact, one of the end 
products of DNA catabolism. Moreover, DNA is presumably particularly abundant 
in this case. 
The origin of the taurine excreted under the influence of X-irradiation might be 
slightly different. As shown in the section BLOOD POOLS OF FREE AMINO ACIDS (p. 241), 
taurine is a typical intracellular component, the concentration of which is remark- 
ably higher in leucocytes and platelets than it is in the surrounding plasma. Taurine 
also is one of the end products of the oxidative metabolism of the sulfur amino 
References p. 261/262 
