Accumulation of [3H]Sialyl-conjugates in sialidosis (sialidase-deficient) fibroblasts cultured in the presence of [3H]-N-acetylmannosamine

Skin fibroblasts from normal individuals and a patient with the infantile form of sialidosis were cultured for up to 72h in medium containing [³H]-N-acetylmannosamine. The sialidosis fibroblasts consistently accumulated more labeled compound(s) than the control cells, i.e. 37–88% more cpm per mg protein. Precipitation of sonicates of these cells with 10% trichloracetic acid, TCA, demonstrated that the excess radioactivity in the sialidosis fibroblasts was in one or more TCA soluble compounds. There was no detectable difference in the amount of label in the TCA insoluble material.