['To examine whether urotensinII (UII) induces hypertrophy of neonatal rat cardiomyocytes cultured in vitro.', 'The primary cardiac myocytes cultured for 40 h followed by further culture in serum-free media for another 24 h were subjected to exposure to UII of varied concentrations for 24 h, after which the changes in the size of the cells were analyzed by flow cytometry with (3)H-leucine incorporation also measured.', 'At the concentration of 1x10(-7) mol/L, UIIcould increase the size of the cultured cardiac myocardial cells (P=0.021) and 3H-Leucine incorporation (P=0.015).'] Does [ Urotensin II induce hypertrophy of in vitro cultured neonatal rat cardiac myocytes ]?