Mammary gland tumors are related to variation in the levels of free L- and D-amino acids in canine plasma and urine

Abstract

For malignant mammary gland tumor (MGT), the risk of metastasis to other organs increases as the stage progresses, making it difficult to cure. For this reason, early detection and treatment are extremely important. The purpose of this study is to investigate whether L- and D- free amino acids can be biomarkers for MGT. Plasma and urine samples were collected from normal and MGT dogs. Randomly obtained samples were subjected to L- and D-amino acid analysis. In L-type plasma free amino acids, L-arginine was lower in MGT dogs than in normal dogs. It was suggested that the plasma content may have decreased because Larginine was taken up by cancer cells. As for D-type plasma-free amino acids, the D-alanine level was lower in the MGT dogs than in the normal dogs. Our investigation suggested that identifying changes in specific free amino acids in the plasma and urine might work as a method of diagnosis.