【摘要】 本文根据扫描电镜观察,报告了dbcAMP引起小鼠U₁₄腹水瘤细胞微绒毛和质膜表面的细微形态变化。U₁₄腹水瘤的多数细胞体积大,大小相近,表面有许多细长微绒毛;微绒毛表面和微绒毛间细胞质膜表面,仅见很细微的点状微突。腹腔内注射dbcAMP的U₁₄腹水瘤,85％以上的细胞体积缩小,大小不等,表面微绒毛缩短且减少。在没有微绒毛的部位,细胞质膜表面有许多颗粒状微突起,较对照组明显易见。微绒毛表面也有与之大小类似的微突起,使微绒毛表面凹凸不平。流式细胞光度计分析结果表明,在本文实验条件下,dbcAMP未引起U₁₄腹水瘤细胞周期的变化,细胞膜表面和微绒毛的变化,也不单纯是细胞周期中微绒毛数量和分布的改变。因此作者认为,这些变化不是通过改变细胞周期引起的。 cAMP引起微绒毛退缩的机制不详。至于微绒毛间的颗粒状微突起是微绒毛退缩的遗迹,抑或是由cAMP引起,尚待研究。cAMP引起瘤细胞表面形态的变化,进一步证明了cAMP在小鼠体内诱导恶性细胞分化的作用。更多还原

【Abstract】 dbcAMP was injected i. p. into four U₁₄ ascitic tumor bearing mice on 3,4,5,6 and 7 days after inoculation of tumor cells. The ascites was aspirated 0.5-1 hour after last injection. For scanning electron microscopy, the tumor cells, washed twice in Hanks solution, were fixed in glutaraldehyde and OsO₄, dehydrated with ethyl alcohol and dried with camphene. For flow microcytometric analysis, the treated tumor cells were fixed in 70% cold ethyl alcohol and stained with propidium iodide. Under SEM, the untreated tumor cells were large, spherical, and uniform in size with numerous long thin microvilli on the cell surface. A few barely visible minute protrusions were present on the microvilli and cell membrane. The great majority of treated tumor cells became smaller and variable in size, with shortened microvilli which reduced in number and even disappeared in some area. Many granular protrusions, larger than that of the control, were clearly observed on the cell membrane and microvilli. The result of flow microcytometric analysis showed that the DNA histogram and cell cycle profile from dbcAMP treated cells have no significant difference from the untreated controls, so it is evident that morphologic changes resulted from dbcAMP were not caused by cell cycle alteration. The morphogenesis of microvilli and cell membrane changes in dbcAMP treated cells is not clear. The relation of these configurations to differentiation of malignant tumor cells is discussed.更多还原