Effect of insulin on the incorporation of ³H-inositol into the inositol phospholipids (PI, PIP, PIP₂) and Glycosyl-phoshatidylinositols (GPIs) of Tetrahymena pyriformis

The unicellular tetrahymena contains inositol phospholipids (PI, PIP, PIP₂) and GPIs. Treatment with 10⁻⁵M insulin decreases the total ³H-inositol incorporation and incorporation into PI. 24 h after 10⁻⁶M insulin treatment there is an elevation of these parameters. Second treatment with 10⁻⁶M insulin doubles and 10⁻⁵M decreases these levels. This means that the effect on phosphoinositide turnover by insulin in Tetrahymena is rather concentration dependent. Inositol incorporation into GPIs is also influenced by insulin.