Mn++-stimulated 3H-inositol incorporation in cultured vascular smooth muscle cells: deficiency in cells from spontaneously hypertensive rats.
Incubation of cultured dissociated aortic smooth muscle cells from Wistar-Kyoto rats (WKY) with Mn++ resulted in a 10-fold stimulation of 3H-myo-inositol incorporation into membrane phospholipid. The stimulation was temperature and energy dependent. The Mn++ EC50 was 1 mM and maximum stimulation occurred at 10 mM Mn++. Other cations were ineffective. In cells from spontaneously hypertensive rats (SHR), the Mn++ EC50 was unchanged whereas the maximum stimulation of 3H-inositol incorporation was reduced by 50% compared to cells from parallel WKY cultures. These results suggest that in SHR cultured vascular smooth muscle cells there is a deficiency in an enzymatic process mediating exchange of free inositol with the headgroup inositol of membrane phosphatidylinositol.
D000818:Animals; D002478:Cells, Cultured; D006973:Hypertension / Q000378:metabolism*; D007294:Inositol / Q000378:metabolism*; D008345:Manganese / Q000494:pharmacology*; D009131:Muscle, Smooth, Vascular / Q000187:drug effects / Q000378:metabolism*; D010716:Phosphatidylinositols / Q000378:metabolism; D051381:Rats; D011918:Rats, Inbred SHR; D011921:Rats, Inbred WKY; D014316:Tritium
D010716:Phosphatidylinositols; D014316:Tritium; D008345:Manganese; D007294:Inositol