MTX诱导神经管畸形动物模型的建立

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

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)(P<0.05;P<0.05)。MTX实验组的胚胎组织中DHFR的活性较对照组显著降低(P<0.05),5-MeTHF和5-FoTHF的浓度和对照组相比也明显降低(P<0.05)。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。

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 ofhindbrain 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： NTDs animal model induced by folate deficiency was successfully established.