IN-VIVO EFFECT OF HIGH-ENERGY SHOCK-WAVES ON GROWTH AND METASTASIS OFTHE HETEROGRAFTED TUMORS OF NUDE-MICE

Objectives. To examine whether high energy shock waves (HESW) can inhi bit tumor growth in vivo and whether it can promote the metastasis of the heterografted tumors of nude mice. Materials and Methods. Observat ions were made on the effect of HESW on tumor growth, histological and ultrastructural (transmission electron microscope, TEM) variations an d metastasis to lymph nodes and viscera in the nude mice with heterogr afted tumors. The Dornier HM, lithotripter was used under the working voltage of 15 kV, the impulse number being 0, 400 and 800 respectively , the temperature of waterbath, 35-37 degrees C and the impulse rate, 60 / min. Results. HESW did have cytotoxic effect on tumors in vivo, i ncluding acute and chronic lethal effects and growth inhibitory effect , and it could act on levels of cell membrane, cytoplasmic organelles and nuclear chromatin. At a definite working voltage, this effect was positively proportional to the impulse number. The action mechanism of HESW in vivo might be direct mechanical damage and indirect inhibitio n of tumor growth as a result of causing damage to the blood sup ply. Histological examination showed no metastatic foci to the lymph nodes and viscera of the nude mice with the heterografted tumors. Conclusion s. HESW do inhibit tumor growth in vivo, but temporarily. This observa tion showed no tumor metastasis in the nude mice after the impulsion o f HESW, but further studies on this topic are needed. It can be predic ted that HESW will become a clinical method to treat the tumors after further investigation on its mechanism of action.