Action of insulin on glycogen metabolism in cultured hepatoma cells.

ZHC cells, an established hepatoma cell line characterized by its capacity to synthesize and store glycogen, retain responsiveness to insulin. Sensitivity to insulin is correlated with culture development and is maximal in the confluent monolayer cultures. Insulin induces, within 2-3 h, an increase of glycogen content by stimulating the net synthesis of new glycogen molecules and without affecting their breakdown. Insulin directly acts on glycogen metabolism, and does not modify total cell protein or DNA synthesis. The ZHC cell line can provide a new model for the study of insulin regulation of glycogen metabolism, in the absence of other hormones that modulate the same pathway.