[Alteration of inositol phosphate metabolism in aortic smooth muscle cells from spontaneously hypertensive rat].

The changes of inositol phosphates in quiescent and GTP gamma S activated vascular smooth muscle cells (VSMC) derived from aorta of spontaneously hypertensive rat (SHR) were examined. The inositol phosphate assay revealed that there was no difference in the inositol-1, 4, 5-triphosphate (InsP3) level between the quiescent VSMCs of SHR and that of normotensive Wistar-Kyoto rats (WKY). G-protein activator GTP gamma S caused a dose- and time-dependent increase in the InsP3 level in VSMCs. Activated G proteins increased significantly the InsP3 level in VSMCs of SHR. In conclusion, the highly sensitive reactivity to GTP gamma S in the generation of InsP3 in VSMCs from SHR may be related to the possible abnomality of the number, substructure or function of some components in G proteins, phosphoinositide turnover.