Use of loperamide as a phenotypic probe of mdr1a status in CF-1 mice
Use of loperamide as a phenotypic probe of mdr1a status in CF-1 mice
复制标题
DOI：
10.1023/b:pham.0000045241.26925.8b
复制
发表时间：
2004-10-01
影响因子：
3.7
通讯作者：
Pollack, GM
中科院分区：
文献类型：
--
作者：
Kalvass, JC;Graff, CL;Pollack, GM
目的. CF-1小鼠品系的一个亚群（约25%）缺乏P-gp表达，因此，在这些动物中观察到许多底物的脑渗透增加。缺乏mdr 1a基因的小鼠代表了研究P-gp对CNS底物处置的潜在影响的重要研究工具。在所有实验中使用成年CF-1小鼠。在给药后0.25、2和4 h通过热板潜伏期试验测定洛哌丁胺诱导的抗伤害感受。在药效学实验结束时，采集躯干血液和脑组织，并通过高效液相色谱-质谱法（LC-MS/MS）进行分析。通过RT-PCR对小鼠进行mdr 1a基因分型。所有小鼠的最大热板潜伏期（60秒）的三个连续的影响表现出相当大的阿片样行为，除了抗伤害。没有连续三次最大热板潜伏期效应（小于或等于30 s）的小鼠没有表现出阿片样行为。与P-gp活性动物相比，鉴定为P-gp缺陷小鼠的洛哌丁胺脑-血清比高65倍（10.1 +/- 1.0 vs. 0.155 +/- 0.018）。所有经热板法鉴定为P-gp活性的动物均为mdr 1a（+/+）基因型。该测定似乎通过相对非侵入性的简单技术提供了快速和明确的测量，以鉴定CF-1小鼠亚群中的P-gp状态。
Purpose. A subpopulation of the CF-1 mouse strain ( approximately 25%) lacks P-gp expression, and consequently, increased brain penetration of many substrates is observed in these animals. Mice lacking the mdr1a gene represent an important research tool to study the potential effects of P-gp on CNS substrate disposition.Methods. Adult CF-1 mice were used in all experiments. Loperamide-induced antinociception was determined by the hotplate latency test at 0.25, 2, and 4 h post-dose. At the conclusion of the pharmacodynamic experiment(s), trunk blood and brain tissue were collected and analyzed by high-performance liquid chromatography-mass spectrometry (LC-MS/MS). Mice were also genotyped for their mdr1a status via RT-PCR.Results. All mice with three consecutive effects of maximum hotplate latency (60 s) showed considerable opioid-like behavior in addition to antinociception. Mice without three consecutive effects of maximum hotplate latency (less than or equal to30 s) showed no opioid-like behavior. The loperamide brain-to-serum ratio in mice identified as P-gp-deficient was 65-fold higher compared to the P-gp-competent animals (10.1 +/- 1.0 vs. 0.155 +/- 0.018). All animals identified as phenotypically P-gp competent based on the hotplate assay evidenced the mdr1a(+/+) genotype.Conclusion. This assay appears to offer a rapid and unambiguous measure via a relatively non-invasive, simple technique to identify P-gp status in the CF-1 subpopulation of mice.