Using [3H]myo-inositol labeled frog skeletal muscles, we have studied the effect of high K+ exposure on phosphoinositide metabolism. After 12 hours labeling, 80mM K+ exposure induced a time-dependent change. The labeling associated with phosphatidylinositol(PI) and phosphatidylinositol 4-phosphate(PIP) gradually increased and decreased, respectively. The labeled phosphatidylinositol 4,5-bisphosphate(PIP2) first decreased, and then recovered. An accumulation of the labeling in inositol phosphates was shown. In shortening the labeling to 30min, 15min high K+ exposure was found to only increase the labeling in all fractions. Taken together, these results show that high K+ exposure can activate the turnover of phosphoinositides, which is consistent with the hypothesis that the metabolism of phosphoiositides may regulate excitation-contraction(e-c) coupling.
|Original language||English (US)|
|Number of pages||6|
|Journal||Biochemical and Biophysical Research Communications|
|State||Published - Jan 31 1992|
ASJC Scopus subject areas
- Molecular Biology
- Cell Biology