The effects of IGF-1 on cellular phospholipids.

Signals are transduced across the cell membrane through a series of events that are triggered by the activation of receptors or opening of ion channels. It is evident that the stimulation of cells can elicit a series of catabolic cascades, which cause degradation of several membrane phospholipids. Several breakdown products participate directly in the intracellular signaling cascade. The objective of this study was to establish the changes in phospholipid pools of MG-63 cells in 15 and 30 minutes after stimulation with IGF-1, which is a known growth factor. After collection of the cells, methods were performed to prepare the samples for thin-layer chromatography. Silica gel plates were analyzed for each experiment for quantitative and qualitative data. The cells were also tested for alkaline phosphatase activity. The highest percent of radioactivity was within the phosphatidylcholine fraction of control cells at 15 minutes and phosphatidylserine at 30 minutes. The highest percent of radioactivity was in the phosphatidylserine fraction at 15 minutes and increased after 30 minutes in IGF-1 treated cells.