Stimulative effects of insulin on Toxoplasma gondii replication in 3T3‐L1 cells

Abstract The influence of insulin and 2‐deoxy‐glucose ( d ‐glucose) on the intracellular protozoan Toxoplasma gondii replication in 3T3‐L1 cells was investigated. Insulin and d ‐glucose had a dose‐responsive mitogenic effect on intracellular T. gondii replication and development in 3T3‐L1 cells. Insulin concentrations between 10 −2 and 10 −1 μg/ml combination of 4.5 g/l d ‐glucose in DMEM medium gave maximum stimulus to T. gondii replication. The number of tachyzoites increased rapidly, with the growth peaking typically on day 3 or 4 of culture, and then declining quickly. However, insulin, in the absence of d ‐glucose, had comparably less effect on T. gondii growth than two of their combination. d ‐glucose concentrations significantly affected the tachyzoite replication and appear to be indispensable for maintaining the host 3T3‐L1 cells.