LYSOPHOSPHATIDIC ACID ACTIVATES NUCLEAR NUCLEOSIDE TRIPHOSPHATASE IN RAT HEPATOCYTES

LYSOPHOSPHATIDIC ACID ACTIVATES NUCLEAR

NUCLEOSIDE TRIPHOSPHATASE IN RAT

HEPATOCYTES

李菊香;李载权;伍期专;唐朝枢;杜军保

【期刊名称】《中国医学科学杂志（英文版）》 【年(卷),期】2003(018)004

【摘要】Objectives. To observe if lysophosphatidic acid (LPA) can influence nuclear nucleoside triphos-rnphatase (NTPase) activity of isolated hepatocyte from rat, and to investigate the possible mechanisms byrnwhich LPA affects the NTPase. Method. Isolated and cultured hepatocytes from rat liver were exposed to LPA (1×10-9, l×10-8 and 5xl0-8mol/L) with or without inhibitors of protein kinase C (PKC) and mitogen activating protein kinasernkinase (MAPKK), and the NTPase activity on nuclear envelope was assayed using ATP and GTP as substrate, respectively.rn Results. Nuclear NTPase activity of rat hepatocytes was potently stimulated by incubation of hepato-cytes with LPA in concentration- and time-dependent manners. In hepatocytes incubated with LPA, nuclear NTPase activity was significantly higher than that of the control (P<0.01). In hepatocytes preincu-bated with PKC inhibitor H-7 or MAPKK inhibitor PD98059, LPA-stimulated activation of nuclear NT-Pase was obviously attenuated. In addition, direct incubation of isolated hepatic nuclei with LPA had no effect on nuclear NTPase