DRUG TRANSFER AND EXPRESSION OF P-GLYCOPROTEIN IN THE RAT 9L GLIOMA

大鼠 9L 胶质瘤中的药物转移和 P-糖蛋白的表达

基本信息

批准号：
03454347
负责人：
YAMASHIMA Tetsumori
金额：
$ 4.1万
依托单位：
KANAZAWA UNIVERSITY
依托单位国家：
日本
项目类别：
Grant-in-Aid for General Scientific Research (B)
财政年份：
1991
资助国家：
日本
起止时间：
1991 至 1992
项目状态：
已结题

项目摘要

Two weeks after the inoculation of 1.5x10^5 of 9L glioma cells into the rat brain, the transfer of radiolabelled drugs into the brain and the experimental 9L glioma during the first cerebral circulation,was measured with a liquid scintilation counter and analyzed by the method of Oldendorf. The expression of P-glycoprotein, which is known to be associated with the efflux of drugs, was also studied, using anti-P-glycoprotein monoclonal antibody: C-219. Furthermore, the ultrastructure of brain capillaries, tumor vessels and glioma cells was studied by conventional and immuno-electron microscopy. Sucrose (control), the transport of which through the blood-brain barrier is known to be saturable, accumulated to 5 fold higher levels in the tumor relative to brain. MCNU (ranimustine: methyl 6-[3-(2-chloroethyl-3-nitrosoureido]-6-deoxy-alpha-D-glucopyranoside), 5-FU (5-fluorouracil) and doxorubicin (Adriamycin) showed quite little accumulation into the normal brain, whereas ACNU (nimustine: 1-(4-amino-2-methyl-5-pyrimidinyl) methyl-3-(2-chloroethyl)-3-nitrosourea hydrochloride) showed an increased accumulation. MCNU and doxorubicin showed negligible accumulation in the glioma cells despite diffusion into the tumor interstitial space. In contrast, ACNU and 5-FU showed an increased accumulation in tumor cells. The transfer of 5-FU into the cultured 9L glioma cells was decreased by ATP inhibitors or by low temperature. Although both brain capillary endothelial cells and glioma cell membranes were immunohistochemically positive for P-glycoprotein, the tumor vasculature showed low expression of P-glycoprotein. The endothelial cells of tumor vessels ultrastructurally showed increased fenestrations, swelling and disrupted junctions. Accordingly, it is suggested that hydrophilic drugs such as doxorubicin, being pumped out by P-glycoprotein, do not accumulate in 9L glioma as do other lipophilic drugs such as ACNU, or 5-FU associated with the carrier-mediated mechanism.

接种9L神经胶质瘤细胞进入大鼠脑的1.5x10^5后两周，通过液体闪烁柜台测量了放射性标记的药物向大脑的转移，并在第一个大脑循环过程中转移了实验9L胶质瘤，并通过Oldendorf的方法进行了分析。还使用抗P-糖蛋白单克隆抗体：C-219研究了已知与药物外排相关的P-糖蛋白的表达。此外，通过常规和免疫电子显微镜研究了脑毛细血管，肿瘤血管和神经胶质瘤细胞的超微结构。蔗糖（对照），已知通过血脑屏障的运输饱和，相对于脑而言，肿瘤中的水平高于5倍。 MCNU（ranimustine：甲基6- [3-（2-氯乙基-3-硝基Rosoureido] -6-脱氧-Alpha-alpha-D-d-葡萄糖苷），5-FU（5-氟尿嘧啶）和阿霉素（阿霉素）（adriamycin）表现出很少的积累到正常的脑中，而不是正常的ACNU（NIMEAS ACNU） 1（4-氨基-2-甲基-5-吡二酰胺）甲基-3-（2-氯乙基）-3-硝基苯甲酸盐盐酸的积累增加5-FU通过ATP抑制剂或低温降低了培养的9L胶质瘤细胞。因此，建议通过P-糖蛋白泵出的致亲水药物（如阿霉素）不会像其他亲脂性药物（如ACNU）或与携带者介导的机制相关的5-FU中积聚在9L神经胶质瘤中。