MTX诱导神经管畸形动物模型的建立

目的:通过二氢叶酸还原酶(DHFR)竞争性抑制剂甲氨蝶呤(MTX)建立叶酸缺乏的神经管畸形(NTDs)动物模型。方法:本研究用孕7.5天C57BL/6J小鼠,采用腹腔注射(ip)不同剂量的MTX建立叶酸代谢障碍的小鼠NTDs模型,LC/MS/MS及酶学方法检测胚胎组织中叶酸相关代谢产物水平及DHFR活性。结果:最佳的致畸剂量为,MTX 4.5 mg/kg,其NTDs发生率最高为31.4%。畸形的胎鼠表型多数为后脑泡未闭,且其身长(4.21±0.76),体重(9.49±3.48)均明显低于对照组(6.32±0.56;22.76±3.23)(P0.05;P0.05)。MTX实验组的胚胎组织中DHFR的活性较对照组显著降低(P0.05),5-MeTHF和5-FoTHF的浓度和对照组相比也明显降低(P0.05)。结论:本研究成功的建立了叶酸缺乏的神经管畸形动物模型。

The Establishment of Folate Deficiency-related Animol Model of Neural Tube Defects by MTX

Objective:To establish the animal model of neural tube defects (NTDs) by folate deficiency induced dihydrofolate reductase (DHFR) inhibitor, methotrexate (MTX).Methods:The NTDs animal model was established by intraperitoneal injection of different doses of MTX into pregnant C57BL/6J mice on gestational day 7.5. Folate-related metabolic products and DHFR activity in embryo tissues were measured by using LC/MS /MS assay.Results:MTX with the dose of 4.5 mg/kg induced the highest incidence of NTDs (31.4%) and was considered as the optimal teratogenic dosage. Most NTDs exhibited the failure of hindbrain closure of the neural tube and the body length (4.21± 0.76) and weight (9.49± 3.48) decreased significantly compared with that in the control group(6.32± 0.56 vs 22.76± 3.23), (P<0.05 vs P<0.05). DHFR activity and concentrations of 5-MeTHF and 5-FoTHF were obviously lower than that in the control group after MTX treatment (P<0.05).Conclusion:animal model induced by folate deficiency was successfully established.