The changes in the amount and function of G proteins of resistance vascular smooth muscle from the rats with hypertension and congestive heart failure

1）。采用免疫组织化学方法测定了4、10和20周龄自发性高血压大鼠、同龄对照组、Wistar-Kyoto大鼠和单肾一夹继发性高血压大鼠外周阻力血管和主动脉中G蛋白的分布和丰度。与年龄匹配的Wistar-Kyoto大鼠相比，4周龄（高血压发作前）、10周龄和20周龄的自发性高血压大鼠提睾肌动脉平滑肌中Gi或Gs样免疫反应物的浓度显著降低。相比之下，没有显着差异检测到的丰富的Gi或Gs之间的主动脉平滑肌的自发性高血压大鼠和Wistar-Kyoto大鼠，或之间的阻力动脉平滑肌的继发性高血压和对照组大鼠。SHR外周阻力血管平滑肌中Gi和Gs的浓度和功能的早期变化可能反映了受体介导的信号转导受损，并可能参与了高血压的发病机制。充血性心力衰竭大鼠阻力小动脉α 2-Gi系统功能较假手术对照组降低。目前对Gs和Gi蛋白的含量以及Gs的功能研究正在进行中。

1). The localization and abundance of G proteins in a peripheral resistance vessel and the aorta were determined immunohistochemically in the 4-, 10- and 20-week-old spontaneously hypertensive rats, age-matched control, Wistar-Kyoto rats, and one-kidney, one-clip secondary hypertensive rats. The concentrations of Gi- or Gs-like immunoreactivity in the smooth muscle of the cremaster artery were significantly lower in spontaneously hypertensive rats at 4 weeks (before the onest of hypertension), 10 weeks and 20 weeks of age, as compared with the age-matched Wistar-Kyoto rats. In contrast, no significant differences were detected in the abundance of Gi or Gs between the aortic smooth muscle of spontaneously hypertensive rats and Wistar-Kyoto rats, or between resistance artery smooth muscle of the secondary hypertensive and control rats. The dilation via beta2-AR-Gs system was decreased in prehypertensive SHR compared with SHR.The constriction via alpha2-Gi system also decreased in SHR compared with WKY.These early changes in the concentration and function of Gi and Gs in the smooth muscle of peripheral resistance vessels in spontaneously hypertensive rats may reflect impaired receptor-mediated signal transduction and may be involved in pathogemesis of hypertensin.2) The function of alpha2-Gi system of resistance small artery was decreased in the rats with congestive haert failure compared with sham-operated control rats. Further study for concentartion of Gs and Gi protein and functional study of Gs are going now.