Factors Affecting Glycogen Levels in HeLa Cells: Prednisolone and Adenine Nucleotides

Summary HeLa cells with an inducible alkaline phosphatase (HeLa S3G strain) contained an increased amount of glycogen when grown from 3 to 4 days in the presence of 0.5μg/ml prednisolone. This effect was due to a decreased degradation of glycogen, not to an increased glycogen synthesis. Glycogen levels were elevated only if prednisolone was present in the culture from the time of inoculation, which indicates a requirement for steroid during the period of initial cell attachment. Glycogen levels could also be increased in the same HeLa cell strain by adenosine or adenine nucleotides, including 3′,5′,-cyclic AMP. In contrast, the level of cellular glycogen was markedly decreased by dibutyryl 3′,5′-cyclic AMP.