Uehara Y, Ishii M, Ishimitsu T, Sugimoto T
Second Department of Internal Medicine, Faculty of Medicine, University of Tokyo, Japan.
Hypertension. 1988 Jan;11(1):28-33. doi: 10.1161/01.hyp.11.1.28.
To explore the roles of vascular phospholipase C activity in the development of hypertension, phospholipase C activity was examined in the aortic wall of spontaneously hypertensive rats (SHR). Phospholipase C activity was significantly enhanced (+87%, p less than 0.005) in 14-week-old SHR as compared with normotensive Wistar-Kyoto rats (WKY). The enzymatic activities were positively correlated with the levels of blood pressure in both of the rat strains (r = 0.62, p less than 0.003). Vascular phospholipase C was also significantly activated (+62%; p less than 0.006) in the aortic wall of 4-week-old prehypertensive SHR, as compared with age-matched WKY. In contrast, vascular phospholipase A2 activity was unaffected in the aortic wall of either adult or very young SHR. There was no difference in the cardiac phospholipase C activity between adult SHR and WKY. The vascular phospholipase C of SHR had a lower Michaelis constant (Km) value than that of WKY. Moreover, its pH profile and calcium requirement differed in part from those of WKY. These results indicate that the activation of vascular phospholipase C precedes the development of hypertension and that the enhancement may be induced by both quantitative and qualitative changes in phospholipase C in SHR.
为探讨血管磷脂酶C活性在高血压发生发展中的作用，对自发性高血压大鼠（SHR）主动脉壁中的磷脂酶C活性进行了检测。与正常血压的Wistar-Kyoto大鼠（WKY）相比，14周龄SHR的磷脂酶C活性显著增强（增加87%，p<0.005）。两种大鼠品系中酶活性均与血压水平呈正相关（r = 0.62，p<0.003）。与年龄匹配的WKY相比，4周龄高血压前期SHR主动脉壁中的血管磷脂酶C也显著激活（增加62%；p<0.006）。相比之下，成年或幼年SHR主动脉壁中的血管磷脂酶A2活性未受影响。成年SHR和WKY的心脏磷脂酶C活性无差异。SHR的血管磷脂酶C的米氏常数（Km）值低于WKY。此外，其pH曲线和钙需求在部分方面与WKY不同。这些结果表明，血管磷脂酶C的激活先于高血压的发生，且这种增强可能是由SHR中磷脂酶C的数量和质量变化共同诱导的。
