Abnormalities of splenic enzyme networks in nude mice

The activities of various hydrolytic enzymes in splenic tissues of nude mice were compared with those of their controls of the same age. Since all of the enzymatic activities varied with age in both nude mice and in the controls, the difference between the two groups were difficult to define clearly. Principal component analysis enabled us to clearly categorize the enzymatic variations of both groups into two main components. One was related to the maturation process of the animals and the other to the pathological processes in the nude mice. The enzymes related especially to the latter component were formyl-methionine aminopeptidase (fMet-AP), mannosidase, and beta-N-acetyl-D-glucosaminidase (GlcNAc-ase). These enzymes may represent the abnormality of the surface of lymphocytes in the nude mice.