372 G. ROUSER, B. JELINEK, A. J. SAMUELS, K. KINUGASA 
Effects of fasting and food intake on the free amino acids of plasma and erythrocytes in 
rabbits 
The effects of fasting and food intake in rabbits were studied particularly in con- 
nection with simultaneous investigations on the effects of nitrogen mustard. The 
results are presented in part IV of this series (Figs. 157-162). The plasma samples 
showed minimal variations and it can be concluded that there are no major changes 
produced by a short fast or normal food consumption. 
CONCLUSIONS 
The data demonstrate a good degree of reproducibility of the chromatographic 
method and point out a number of difficulties and pitfalls that may be encountered 
in studies of this type. Special considerations for the handling of blood from patients 
with leukemia have been disclosed by 7m vitvo incubation studies. 
A marked decrease in some or all amino acids in blood plasma, and to a lesser 
extent in blood cells, has been found to follow venipuncture in both man and animals 
and should be considered in all studies of free amino acids of blood. Previous investi- 
gators have failed to note the response and it is possible that this failure is due to the 
fact that blood samples are usually withdrawn at hourly intervals, whereas the 
venipuncture response occurs within a few minutes and the control level is generally 
reached within one hour. Furthermore, all the amino acids are seldom involved in 
the response and the determination of total amino acid nitrogen or determination of 
a few amino acids may not disclose the changes that frequently take place. 
The study of the effects of eating have disclosed that little or no change is to be 
expected as a result of the intake of food in the morning in the normal manner for 
the patient. Similar results were obtained with rabbits. No consistent effects due to 
fasting for 23 or 33 h or eating were observed upon the free amino acids of plasma 
and erythrocytes of rabbits. 
References p. 447/448 
