前田 一雄, 津崎 恒明

Kazuo MAEDA, Tsuneaki TSUZAKI

鳥取大学医学部産科婦人科学教室

Department of Obstetrics and Gynecology, Tottori University School of Medicine

キーワード : pulsed ultrasound, cultured mammalian cells, bioeffects, acoustic intensity, standard ultrasound generator

Cultured cells of human amniotic origin was exposed to 2 MHz pulsed ultrasound generated by USP-1 generator system at various intensities for 30 to 60 min. Cell suspending medium on the exposure was either phosphate buffered saline solution or Eagle's MEM containing 20% calf serum. Beam width in acoustic field (1.7 cm) was broader than the inner diameter of the cell suspending tube (1.2 cm). Cell growth suppression was estimated by relative growth ratio that was the growth ratios in exposed groups to the control on 2, 4 and 7 days after the exposure. Regression analyses between these relative growth ratios and SATP intensities on 4 and 7 days after the exposure showed linear correlation. Cell growth suppression thresholds in the days were estimated as large as 20.5 W/cm² and 20.0 W/cm² (SATP), and 246 and 240 mW/cm² (SPTA) respectively. Cell growth suppression disappeared after the elevation' of viscosity of the cell suspending medium with the increase of calf serum, and reappeared by the prolongation of exposure time or the increment of temporal peak value.