FREE AMINO ACIDS IN BLOOD. I 363 
rocytes, although such changes are too small to be apparent with the procedure 
finally adopted for the separation of plasma and cells. 
In vitro incubation studies with blood from patients with chronic granulocytic leukemia 
Studies similar to those carried out with blood from chronic lymphatic patients 
were done with blood from chronic granulocytic leukemia patients, and in ad- 
dition an instructive series of incubations (a total of 7 7m vitro studies) were done 
where blood, after being withdrawn in the usual manner, was allowed to stand 
in a centrifuge tube at room temperature (about 25°) for periods up to 4h. The 
blood was then centrifuged and the cells and plasma separated in the usual man- 
ner. It was found that leukocyte free amino acid patterns did not change. Glutamine 
was not degraded and glutamic and aspartic acids were not increased in amount. 
Figs. 29-31 show white cells recovered from whole blood allowed to stand for 
1, 2, and 3h at room temperature without shaking. No definite changes were ob- 
served. 
In contrast to the very consistent pattern obtained from the leukocytes, it was 
found that plasma and red cell samples might show large changes related to the frag- 
mentation of platelets and perhaps white cells, and to the increased difficulty of re- 
moval of the leukocytes from the erythrocyte mass after the blood had stood for 
several hours. From these studies it was concluded that blood from patients with 
chronic granulocytic leukemia should be processed immediately, but that artefacts 
would be unlikely with the procedure adopted for routine work. 
The fall of plasma free amino acids following withdrawal of blood samples 
Studies were carried out to demonstrate the reproducibility of the blood free amino 
acid picture over the period of one day. It became apparent that a fall of plasma and 
cell amino acids could follow a single venipuncture. This decrease of amino acids 
has been observed as early as Io min after a single venipuncture, and appears to 
reach a maximum within 30 min with a return to or near the initial level in about 
1h. The response may not be observed when venipunctures are spaced at intervals 
of 1h or more. The response has been observed in normal and leukemic man and in 
rabbits and is termed the venipuncture response. 
The lowering of the free amino acids of the blood plasma in response to veni- 
puncture has been observed to be most marked for taurine and glutamic acid, al- 
though the levels of other amino acids may decrease. Figs. 32—34 illustrate the 
nature of the response of plasma free amino acids in a chronic granulocytic leukemia 
patient (H. Gol. 4) with a white count of 450 000/mm3. The three samples were 
drawn at 15-min intervals. There was a striking decrease in both taurine and glutamic 
acid as indicated by the arrows in Figs. 32-34. A clear demonstration of the veni- 
puncture response in a rabbit is shown in Figs. 35-39. 15 min after the first blood 
sample was drawn a decrease in most of the amino acids of plasma was observed. 
A return toward control levels was evident in the 30-min sample. 
A patient with chronic granulocytic leukemia (D. Fol., a woman with a leukocyte 
count of 157 000 cells/mm?) who had not received any form of treatment for the dis- 
ease was sampled over a period of 4h beginning at 9.30 in the morning. Just after 
the first sample was taken the patient drank 400 ml of distilled water. The same 
References p. 447/448 
