中国生物工程杂志

Abstract: Objective Study the stimulative effects of different concentrations insulin and D-glucose on Toxoplasma gondii replication in 3T3-F442A cells and determination of its activity so as to establish the optimal growth condition of T. gondii. Methods The tachyzoite concentration was determined by enumeration in a haemocytometer (LEVY counting chamber). The survival of tachyzoites was examined using an MTT assay. Results were expressed as means ±S.E.M. Significance of the data was evaluated by Student's unpaired t-test. Results Insulin concentrations between 10－2 and 10－1 mg/ml combination of 4.5 g/l D-glucose in DMEM medium gave maximum stimulus to T. gondii replication. However, insulin, in the absence of D-glucose, had the least effect on T. gondii growth. D-glucose concentrations significantly affected the tachyzoite replication and appear to be indispensable for maintaining the host 3T3-F442A cells. Conclusion Insulin and D-glucose have a dose-responsive mitogenic effect on intracellular T. gondii replication and development in 3T3-F442A cells and lower concentrations of insulin have a significant positive effect on T. gondii growth though higher concentrations of insulin have a negative effect on T. gondii replication. However, insulin, in the absence of D-glucose, had the least effect on T. gondii growth.