Effects of high pressure on apoptosis and apoptosis--associated proteins of vascular smooth muscle cells of organ--cultured artery {\sl in vitro}

Objective To explore the effects of high pressure on vascular remodeling,the changes of apoptosis and the expression of apoptosis-associated proteins,such as Bcl-2 protein and Bax protein,were studied in vascular smooth muscle cells(VSMC)of an intact artery under high pressure condition exclusively. Methods Common carotid arteries of pigs were cultured at 37℃ with Dulbecco's Modified Eagle Medium containing 10% newborn calf serum at a constant flow rate of no more than 6ml/h within 1,4 and 7 days under 160mmHg and 100mmHg,respectively in a new vascular organ-cultured system in vitro.The changes of microstructure of VSMC were observed by transmission electron microscopy.Bcl-2 and Bax protein expression and apotosis of VSMC were examined by immunohistochemical method and in situ TdT-mediated dUTP nick end labeling(TUNEL). Results The apoptosis rate of VSMC increased at the first day and then decreased under high pressure.The expressions of Bcl-2 protein increased within 7 days in the group of high pressure.The expression of Bax protein increased at the first day and then decreased within 7 days.Conclusion The apoptosis rate and the expression of Bcl-2 and Bax protein changed in VSMC under high pressure.It suggests that the high pressure may regulate apoptosis of VSMC through the changes of apoptosis-associated proteins.