凝集素受体在神经管缺陷发生中作用的研究

STUDY OF THE ROLES OF LECTIN RECEPTORS IN DEVELOPMENT OF THE NEURAL TUBE DEFECTS

雌性金黄地鼠交配后第８天灌服维生素Ａ酸８０ｍｇ／ｋｇ，于给药后不同时间剖腹取胎，石蜡包埋、切片，用刀豆凝集素、麦胚凝集素、花生凝集素和荆豆凝集素为分子探针作亲合细胞化学染色，对神经上皮及其基膜、脊索和神经管周围间充质的相应糖基即凝集素受体进行定性、定位和半定量观察。结果显示，实验组各组胚胎的凝集素染色与正常对照组相比，刀豆凝集素和花生凝集素染色显著增强，而麦胚凝集素和荆豆凝集素染色差异无显著性。说明在神经管形成过程中，过量维生素Ａ酸可使神经上皮细胞表面的刀豆凝集素和花生凝集素的受体糖蛋白异常增多，破坏了细胞粘着和基质粘着之间的协调关系，干扰了神经上皮的增殖和迁移过程，导致了神经管缺陷的发生。

Mated female hamsters were given retinoic acid orally in dose of 80mg/kg body weight on 8th of gestation and dissected at 6, 12, 18, 24,36 hours after treatment. The sections were stained with ConA, WGA, PNA,and UEA. These lectins were used as molecule probes to explore the quality,distribution and semiquntity of the related oligosaccharides-lectin receptors on the embryonic neural epithelium and its basement membrane, notochord and the mesenchyme around the neural tube. The results showed that the staining intensity for ConA and PNA in each treated group was significantly higher than those in the controls; but no difference in staining for UEA and WGA between the treated and control groups. It indicated that excess retinoic acid could cause an increase in amount of the glycoproteins containing ConA and PNA binding receptors on the cells of neural epithelium during neurulation, result in the interference of the coordination between the cell cell adhesion and cell-substrated adhesion disturbing the normal process of proliferation and migration of the neural epithelium. It might be an important way by which excess vitamin A induce neural tube defects.