Time- and concentration-dependence of the growth-promoting activity of insulin and histamine in Tetrahymena. Application of the MTT-method for the determination of cell proliferation in a protozoan model.
The unicellular ciliate Tetrahymena pyriformis was treated with different concentrations of insulin or histamine and at different time points the cell density was measured, using a tetrazolium-based semiautomated colorimetric assay (MTT). The assay was suitable to determine the rate of cell proliferation of Tetrahymena. Insulin in each concentration significantly elevated the cell count up to 3 h. After that, it was neutral or its effect was insignificant. Histamine at 10(-5) M concentration diminished cell count at 3, 5, 7 and 24 h. At 10(-6) M concentration there was no difference and at 10(-7) M concentration it enhanced cell division up to 5 h, after that there being no difference. The two hormones have cell division promoting activity for cells of higher animals and the experiments demonstrate this effect already at a unicellular level.
Hegyesi
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H
Department of Genetics, Cell- and Immunobiology, Semmelweis University of Medicine, Budapest, Hungary.
Csaba
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G
D000818:Animals; D002455:Cell Division / Q000187:drug effects; D004396:Coloring Agents; D004305:Dose-Response Relationship, Drug; D006632:Histamine / Q000494:pharmacology*; D007004:Hypoglycemic Agents / Q000494:pharmacology*; D007328:Insulin / Q000494:pharmacology*; D013769:Tetrahymena pyriformis / Q000166:cytology* / Q000187:drug effects; D013778:Tetrazolium Salts; D013844:Thiazoles; D013997:Time Factors
D004396:Coloring Agents; D007004:Hypoglycemic Agents; D007328:Insulin; D013778:Tetrazolium Salts; D013844:Thiazoles; D006632:Histamine; C022616:thiazolyl blue