Effects of urotensin II on cultured cardiac fibroblast proliferation and collagen type I mRNA expression

Objective To observe the effect of urotensinⅡon cultured cardiac fibroblast collagen typeⅠmRNA expression and proliferation, thereby to explore the role of urotensinⅡin myocardial remodeling in the event of cardiac failure. Methods Cardiac fibroblasts of neonatal Sprague-Dawley rats isolated by trypsin digestion method were stimulated by urotensinⅡ at varied concentrations when the cells reached growth arrest. MTT assay was employed to measure the proliferation and determine the number of the cells, and reverse transcriptional (RT)-PCR used to detect the collagen mRNA expression. Results With the increase of urotenisnⅡconcentration, the optical density at 570 nm of the fibroblasts as shown by MTT assay first increased but then decreased, and remained at a significantly higher level in the cells treated with 1×10-8 or 1×10-9 mol/L urotensinⅡas compared with the control (P0.05). The collagen type ⅠmRNA levels of the cells treated with 1×10-7, 1×10-8 or 1×10-9mol/L urotensinⅡ were significantly higher than that of the control cells (P0.01). Conclusion UrotensinⅡcan directly induce cardiac fibroblast proliferation and significantly increase collagen typeⅠmRNA expression, suggesting the crucial role of urotensin Ⅱ in myocardial remodeling.