Effects Of Urotensin â…¡ On Hypertrophy In Cultured Cardiomyocytes From Neonatal Rats

Effects of urotensin II on hypertrophy in cultured cardiomyocytes from neonatal ratsUrotensin II (UII ),a cyclic neuropeptide , has been found to be the most potent contrictor agent that has the effect of 11 fold more than endothelin-l(ET-l). UII can increase or decrease myocardial contractility dosage dependently. A lot of research on patients,animal model and cultured cells strongly suggest that UII may influence cardiovascular homeostasis as well as pathologic process in congestive heart failure. Myocardial remodeling, manifested as cardiac myocyte enlargement, is known to be the important mechamism of congestive heart failure . However, there are dispute on whether UII is involved in the regulation of cardiomyocyte enlargement. We therefore examine in this work the role of UII has played in the development of cardiomyocyte hypertrophy.Method: Primary cardiac myocytes originally from neonatal rats were cultured for 40 hours followed in serum-free media for 24 hours, then the cell size and cell protein content were analized by flow cytometry, 3H-Leucine incorporation were also measured by liquid scintilation counter after exposed to UII for 24 hours.Result: The 10"7mol/L U II could increase the cell forward scatter(FSC) intensity(P=0.021), cell FITC fluorescence intensity(P=0.000) and the 3H-Leucine incorporation (P=0.015).Conclusion: The 10-7mol/L UII could increase size of cultured neonatal rat myocyte, in rich protein content and promote cell protein incorporating rate. UII might participate in cardiomyocyte hypertrophy, and might take part in myocardial remodeling.