Sialic acids. 13. N-acetylneuraminic acid, hexosamine, and pyruvic acid contents and N-acetyl beta-glucosaminidase activity of normal and cancerous sera

Abstract

Taking as references the mean values (in mg/100 ml of serum) of the sialic acids (as N-acetylneuraminic acid) (69.2 ± 4.6), hexosamines (as glucosamine) (59.4 ± 8.2), pyruvic acid (in plasma) (1.4 ± 0.4) and the N-acetyl-/?-glucosaminidase activity (20.0 ±3.6 urn. of p-nitrophenol liberated by 100 ml of serum in 30 min. at pH= 4.8 and 37° C) determined in 21 normal adults, the values obtained in 76 samples of can­ cer sera, classified in 11 groups, and 9 samples of arthrosis, have been compared. It has been deduced that the mean values of sialic acids, hexosamines and N-acetyl- /?-glucosaminidase for almost all pathological cases are higher than the normal, but not those of the pyruvic acid, which show a big variability; furthermore, some paralle­ lism can be appreciated between the mean values of the respective groups for sialic acids, hexosamines and N-acetil/?-glucosaminidase. After treatment with telegammathe­

rapy, the values of sialic acids are higher than before; those of the hexosamines are a little lower and those of the pyruvic and N-acetyl-j8-glucosaminidase are very irregu­ lar (higher or lower). Finally, some metabolic aspects of the plasma protein-bound carbohydrates are discussed.