Effects of Angiotensin II on the Proliferation and Fibronectin Production of Glomerular Mesangial Cells

Angiotensin Ⅱ (Ang-Ⅱ) is a potent vasoactive hormone which plays an important role in the pathogenesis of glomereulosclerosis. Since glomerulosclerosis is characterized by alterations in both cellularities and the extracellular matrix, we investigate the effects of Ang-Ⅱ on the cellular proliferation and fibronectin production of glomerular mesangial cells. Fibronectin was measured by Western blot analysis and fibronectin mRNA was measured by Northern blot analysis. The results were as follows: (1) Ang-Ⅱ increased [3H]-thymidine uptake of mesangial cells in a dose-dependent manner. (2) Ang-Ⅱ increased the number of mesangial cells in a time-dependent manner. (3) Ang-Ⅱ enhanced fibronectin mRNA expression and its production of mesangial cells in a time-dependent manner. Our results indicate that Ang-Ⅱ is an active stimulant for the proliferation and fibronectin production of glomerular mesangial cells.