关键词: 裸鼠移植瘤, 液氮冷冻, DMSO, 甘油, 琥珀酸脱氢酶活性

Abstract: It has not been done into detail that whether human Xenografted tumors could be frozen in liquid nitrogen(- 196 ),thawed and recovered. A human hepatocellular carcinoma cell line (H91O1 ) and its xenografts were tested by succino dehydrogenase (SDE)activity (MTT test) after freezing and thawing and being studied by electron microscope.Two preservative liquids included lO% DMSo or 1o% glyceroI were adopted for the freezing in which the cells or tissues were controlled to be reduced to a minimum rate of cooling (-0.8t / min) in the gas of liquid nitrogen for 24 hours and programmed in liquid nitrogen.It was shown that H9lOl cells or tissues after freezing and thawing presented a high SDE activity (72%~ 93%). The difference of SDE activity between the cells or tissues preserved in 10% DMSO and that preserved in lO% blycerol were significant (P< 0.01 ). The inoculating efficiency of xenografts stored in 10% DMSO was same to that stored in lO% glycerol. Observation by electron microscoPe, tumor cells frozen by both of the preservative medium showed more"black"cell and less"light"cells. Both"black"and"light"ce1ls showed an integral structure of mitochondria membrane and cytoplasmic membrane. Although there was not a general acceptance of the claims that DMSO was preferable to glycerol as an agent for pre venting different organism from freezing damages, it was satisfactory that xenografts pre served in 10% DMSO could improve the survival rates of tumor cells frozen in liquid nitrogen

Key words: Xenografts in nude mice freezing in liquid nirogen DMSO, glycerol succino dehydrogenase activity