ULTRASOUND INHIBITS THE ADHESION AND MIGRATION OF SMOOTH-MUSCLE CELLSIN-VITRO

This study investigated in vitro the effect of therapeutic ultrasound (ULS) on smooth muscle cell (SMC) function as adhesion, migration and proliferation. Experiments were conducted on aortic SMC in culture. Th e LD,, was established (1.5 W for 15 s at a frequency of 20 kHz) and u sed as standard dose in all experiments. Control SMC and viable sonica ted SMC were compared in each experiment. Migratory capacity decreased 2.4-fold after sonication and stayed reduced for up to 24 h, Adhesion capacity decreased 5.5-fold after ULS, The proliferative capacity was similar to that of nonsonicated SMC, Sonication was accompanied by th e disorganization of cr-SM actin fibers and diminished distribution of vinculin; tyrosinated alpha tubulin and vimentin appeared unaffected. These changes might be responsible for the observed inhibition of SMC adhesion and migration. Sonicated cells exhibited less lamellipodia, membrane collapse and bleb formation. The signal transduction cascade, which involves activation of the phospholipase-C pathway, was unaffec ted by ULS, (C) 1998 World Federation for Ultrasound in Medicine & Bio logy.