25. 超音波誘発化学効果と胸腺細胞致死効果に関する周波数依存性

概要

論文の詳細を見る
Iodine formation from Kl-starch solutions and cell lysis of rat thymocytes in Ar- and N_2O-saturated aqueous solutions induced by ultrasound with various frequencies, 38 kHz, 0.5 MHz, 1 MHz and 2 MHz were examined. The iodine formation was observed in Ar-saturated solutions exposed to 38 kHz, 0.5 MHz, and 1 MHz but not to 2 MHz. In contrast, the cell lysis was observed in all frequencies. In N_2O-saturated cell suspensions, the cell lysis was observed only in the sample sonicated with 38 kHz. No iodine formation was observed in the other samples. The relative ratio of the chemical effect vs. the cell survival at 70% (an example of the physical effect) was the order of frequencies, 0.5 MHz>1.0 MHz>38 kHz>2.0 MHz. Apoptosis of thymocytes estimated by the flow cytometry and the assay of DNA fragmentation increased with time after the isolation. However, no modification on apoptosis of thymocytes by 0.5 MHz ultrasound was observed in both Ar and N_2O saturated solutions. Partial protection was observed on the cell lysis and the viability after sonication with 0.5 MHz in Ar-saturated solution containing a free radical scavenger, cysteamine. These results suggest that chemical effects of ultrasound are prominent at specific frequencies and free radicals due to ultrasonic cavitation affect partially the cell lysis and the loss of viability of rat thymocytes.
日本ソノケミストリー学会の論文