RESUMO
The objective of this study was to investigate the role of signal transduction pathway mediated by Galphaq/11 of the aorta in blood pressure regulation during the development of two-kidney one clip (2K1C) Glodblatt hypertension in the rat. Levels of Galphaq/11-subunit and extracellular signal regulated kinase 1/2 (ERK1/2) of the aorta were measured by Western blot analysis at week 1, 2, 4 or 8 after operation. Phospholipase C (PLC) activity of the aorta was measured by using (3)H phosphatidylinostol (4,5) bisphosphate as a substrate. Both systolic and diastolic blood pressure increased markedly in 2K1C rats at week 2, 4 or 8, whereas, the increase in Galphaq/11 and ERK1/2 expression of the aorta began at week 1 after operation (increased by 57.53% and 40.16%, respectively), and maintained at a high level during week 2 8 compared with time matched controls (P<0.01). PLC activities in the aorta were also increased significantly in 2K1C groups at week 4 and 8 compared with the time matched controls (P<0.05). The results indicate that Galphaq/11-mediated signal transduction pathway of the aorta is activated in 2K1C hypertension, and may contribute to the initiation and maintenance of renal hypertension.