Sialic acid in HeLa cells: effect of hydrocortisone.

HeLa S(3) cells grown in the presence of hydrocortisone contain more sialic acid than their corresponding untreated controls. The percentage of the total sialic acid present in the sedimentable fraction obtained from homogenates of cells treated with hydrocortisone is smaller than that of the corresponding fraction of control cells. In addition to N-acetylneuraminic acid, the chromatographic analysis suggests that HeLa S(3) cells probably contain trace amounts of N-glycolylneuraminic acid.