Insulin activity is generally determined by an in vivo rabbit blood glucose drop assay in research and industriel laboratories. The humane experimental techniques imply the use of alternative invertebrate organisms in place of animals, known as replacement rule of the 3Rs. In this study, we report an alternative in vivo extracellular glucose drop assay using unicellular invertebrate Tetrahymena thermophila to replace the use of rabbit and mouse. This assay has four major steps; growing cells, starving cells, treatment of cells and measurement of glucose drop. In this assay, 0.2 mg/ml of human, porcine and bovine insulins dropped extracellular glucose level to 16%, 14% and 12%, respectively in ten minutes. In addition, mammalian insulins respectively increased the cell area about 19%, 15%, and 16% at 6th hour with statistically significant effect on the cell growth, but not in the cell viability. The results showed that the in vivo Tetrahymena thermophila extracellular glucose drop assay could be used as an alternative assay to replace the mouse or the rabbit insulin blood glucose drop assay.

胰岛素活性通常通过研究和工业实验室中的体内兔血糖下降试验确定。人性化的实验技术意味着使用替代的无脊椎动物生物代替动物，这就是3R的替代规则。在这项研究中，我们报告了使用单细胞无脊椎动物四膜虫嗜热菌的另一种体内细胞外葡萄糖滴定法代替兔子和老鼠的使用。该测定法包括四个主要步骤。生长中的细胞，饥饿的细胞，细胞的处理和葡萄糖下降的测量。在该测定中，人，猪和牛胰岛素0.2 mg / ml在十分钟内分别将细胞外葡萄糖水平降至16％，14％和12％。此外，哺乳动物胰岛素在第6小时分别增加了约19％，15％和16％的细胞面积，对细胞生长具有统计学上的显着影响，但对细胞生存力没有统计学意义。结果表明，体内嗜热四膜虫细胞外葡萄糖滴定法可以替代小鼠或兔胰岛素血糖滴定法。