The amount of amino acids in the blood during cardiopulmonary bypass has been studied in two stages by thin-layer chromatography with modifications necessary for this study. In the first stage fresh heparinized blood was recirculated for four to five hours in a heart-lung machine containing a rotating disc oxygenator and nonocclusive roller pumps. This apparatus caused considerable hemolysis, and there was a definite increase in most of the amino acids. Histidine, proline, hydroxyproline, serine, alanine, threonine, aspartic acid, asparagine, glycine, glutamic acid, tyrosine, and tryptophane showed a marked increase; arginine, lysine, valine, cystine, cysteine, and phenylalanine showed a moderate increase. Leucine, isoleucine, and methionine did not change. In the second part of the study, similar investigations were done on blood and urinary samples taken during open-heart operations on five cases. Eight to ten blood samples and a similar number of urinary samples were studied and evaluated repeatedly. The apparatus used, which contained a stationary screen oxygenator and occlusive roller pumps, caused minimal hemolysis. The amino acids increased similarly during open-heart surgery, and this increase continued until four hours postoperatively. During the actual bypass the renal excretion of amino acids slowed down considerably; however, on the evening of the operation there was an increase which continued for four to five days. The hyperamino-acidemia seemed to be related to plasma protein breakdown.
- © 1965 American Heart Association, Inc.