FREE AMINO ACIDS IN ANIMAL TISSUE 309 
“aE : 

Ee 
e 131 132 
Figs. 129-132. For legend see p. 308. 
special retention factors related to adsorption, sequestration in organelles, etc. In 
the course of attempting to elucidate some of the mechanisms which might be of 
importance in regulating the patterns of the freely extractable ninhydrin-reactive 
constituents of tissues, a variety of physiological changes were attempted. It was 
found that the distribution of free amino acids and related substances in the tissues 
of the various animals studied are remarkably constant in the face of a variety of 
induced physiological changes and that only cell death could lead to a virtually 
complete loss of these constituents from a tissue. 
The influence of myocardial infarction on free amino acids of dog heart 
It was of particular interest to follow the changes in free amino acids in cells of a 
tissue undergoing progressive irreversible damage and to attempt to correlate the 
changes in the patterns of these constituents with the cellular changes observed. In 
one such study the free or easily extractable amino acids were determined chromatog- 
raphically in the hearts of dogs at various time intervals up to 6 days after the 
production of experimental myocardial infarction by ligation of the anterior des- 
cending coronary artery?!. Comparisons were made of the infarcted and non-in- 
farcted areas of the left ventricle. 
Typical results are shown in Figs. 107-120. For each time interval after ligation 
it was possible to compare the infarct with a grossly normal area of the same ven- 
tricle. Numerous comparisons were made of normal and infarcted areas of hearts of 
different dogs. The experimental procedure did not appear to produce profound 
effects on the distribution of free amino acids in those areas of myocardium which 
References p. 348/349 
