THE EFFECT OF ox-LDL AND SIMVASTATIN ON PKC ACTIVITY AND CYTOSOLIC FREE Ca~(2+) IN CULTURED RAT AORTIC SMOOTH MUSCLE CELLS
- VernacularTitle:氧化低密度脂蛋白及辛伐他汀对平滑肌细胞信号通路蛋白激酶活性和胞浆内游离钙的影响
- Author:
Jinchuan YAN
;
Zonggui WU
;
Lingzhen ZHANG
- Publication Type:Journal Article
- Keywords:
oxidized low density lipoprotein;
simvastatin;
smooth muscle cell;
protein kinase C;
calcium
- From:
Medical Journal of Chinese People's Liberation Army
1981;0(04):-
- CountryChina
- Language:Chinese
-
Abstract:
The change of PKC activity and cytosolic free Ca 2+ induced by oxLDL and simvastatin in ASMC were measured by its ability to transfer phosphate from 32P-ATP to lysine-rich histone and flow cytometric analysis loading with the Ca 2+ dye fluo-3/Am, respectively. As a result, oxLDL increased total PKC activity in a dose-dependent manner with phase peaking at 14 min, then decreased slowly and maintained for at least 30 min, while oxLDL induced biphasic [Ca 2+]i responses including rapid initial transient phase and sustained phase. Removal of extracellular Ca 2+did not inhibit the rapid phase of oxLDL-induced rise in [Ca 2+]i, but abolished the sustained phase of [Ca 2+]i in response to oxLDL. Activity of PKC was markedly decreased and simvastatin did not impair the initial peak in response to oxLDL but significantly reduced the subsequent plateau phase when simvastatin was added. The results suggested that oxLDL can induce dynamic changes of signal transduction of PKC and cytosolic free Ca 2+in ASMC. The rapid initial transient phase was due to the mobilization of [Ca 2+]i from intracellular Ca 2+ pool and the sustained phase resulted from the influx of extracellular Ca 2+. The inhibition of PKC activity induced by simvastatin may contribute to the changes of intracellular Ca 2+.
