EN
The activity of phospholipase C (PLC) in the aortas of spontaneously hypertensive rats (SHR) was higher than in the aortas of age-matched normotensive Wistar-Kyoto rats (WKY). This was associated with the higher level of inositol 1,4,5-trisphosphate and diacylglycerol in aortas of SHR compared to the level of these compounds found in aortas of WKY. Observed changes in PLC activity correlates with changes in phospholipid composition of SHR aortas. The sphingomyelin (SM) to total phospholipid ratio decreased significantly in aortas of SHR compared to WKY. Since, SM was proposed to be the major PLC δ inhibitor in vivo (Arch. Biochem. Biophys. 297 (1992) 328-333) it might be possible that observed higher activity of PLC in aortas of SHR results from decreased content of this phospholipid.