Phospholipids of Trypanosoma cruzi: Increase of polyphosphoinositides and phosphatidic acid after cholinergic stimulation*

We have studied the effect of carbamoylcholine in Trypanosoma cruzi epimastigote forms prelabelled with [32P]-Pi. Suspensions of cells were incubated at 28°C to measure changes in the levels of [32P]-labelled phospholipids after stimulation. The presence of this cholinergic agonist induced changes in the phosphoinositide metabolism; a shift in the levels of phosphatidylinositol 4,5-bisphosphate (PIP2), phosphatidylinositol 4-phosphate (PIP) and phosphatidic acid (PA) was observed, whereas the levels of the other glycerophospholipids were not changed. This study shows that carbamoylcholine either directly or indirectly influences changes in phosphoinositide metabolism.