Tumor host relationships. I. Effects on free amino acid concentrations of certain tissues.

One of the major effects of the presence of a neoplasm on the host is a disturbance of the pro tein metabolism (8,13). Efforts have been made to take advantage of this for diagnostic purposes by determining some particular change in the con tent or the properties of the plasma proteins (1, 6, 7). These efforts have had a very limited success, because it was found that the observed effects did not develop early, nor were they specifically re lated to the neoplastic process. The present investigation on the effect of can cer on the free amino acid concentrations of blood plasma and tissues was undertaken for the two fold purpose of gaining further information on the derangement in protein metabolism induced by neoplasms, and also in the hope that observed changes might be of such a character as to offer promise of diagnostic usefulness. The latter hope was not realized. The investigation was made feasible by the development in recent years of more sensitive methods for the analytical deter mination of most of the individual amino acids, i.e., by microbiological assay (MBA) and by ion exchange column chromatography.