Bioeffect of ultrasound on endothelial cells in vitro.

The effects of low-intensity ultrasound (US) on biological systems have been investigated extensively; however, the effects of ultrasound stimulation on endothelial cells were rarely studied. In this study, 1 MHz, pulsed 1:4, and four different spatial-average temporal-peak intensities (0.5, 1.0, 1.6, and 2W/cm2) of ultrasound were used to stimulate endothelial cells for 10 min per day. The results showed that ultrasound (intensity 1.6-2.0W/cm2) treatment after 6 days enhanced the nitric oxide (NO) and Ca2+ release from the endothelial cells but did not promote cell growth. In addition, ultrasound stimulation changed the cellular morphology and orientation, and increased extracellular matrix secretion from endothelial cells.