Teratologic effects of Bis-diamine on cardiovascular development in rat embryo : in vivo and in vitro analysis

为了了解双二胺对不同发育阶段大鼠的致畸作用，我们研究了妊娠10、11、12天单次注射200 mg双二胺的Wister母鼠的胚胎和胚胎(分别为组1、组2和组3)。第1组(86例)新生儿主动脉弓畸形发生率为100%，第2组(95例)和第3组(108例)分别为主动脉弓畸形和动脉干畸形92.8%，主动脉弓畸形和法洛四联症45.4%。为了研究双二胺对胚胎早期形态的影响，我们按照Cockroft和New(1978)所描述的方法，对每组的四个胚胎进行了24小时的培养。组1的胚胎表现为神经管延迟闭合和未成熟的心环，并伴有未分化的第三、第四和第六Nortek弓。用抗N-CAM抗体进行免疫组织化学研究发现，N-CAM阳性细胞散在分布于神经管周围。第2组胚胎脑室增大、扩张，流出道呈弧形、细长，可见返流血流，对照组未见。此外，其中两个胚胎有部分心包缺陷。从神经管到心脏的N-CAM免疫阳性链清晰可见，尽管与对照组相比很薄。结果提示，双二胺可能干扰心脏神经棘或间充质细胞的正常发育和迁移，从而导致不同发育阶段的心血管畸形。

Bis-diamine administration to pregnant rats induces conotruncal anomalies.To know teratologic effects of bis-diamine depending on the developmental stage, we examined neonates and embryos from Wister mother rats to which a single dose of 200 mg his-diamine was administered at 10, 11, or 12 days of gestation (group 1, 2, and 3, respectively). The neonates from group 1 (n 86) had aortjc arch anomalies in 100 %, and those from group 2 (n = 95) and 3 (n = 108) had aortic arch anomalies and truncus arteriosus communis in 92.8%, and aortic arch anomalies and tetralogy of Fallot in 45.4%, respectively. In order to examine the early morphological effects of bis-diamine, we cultured four embryos from each group for 24 hours following the procedures described by Cockroft and New (1978). The embryos from group 1 showed delayed closure of the neural tube and immature cardiac looping with undifferentiated third, fourth, and sixth Nortek arches. Immunohistological study using anti-N-CAM antibody revealed that N-CAM positive cells were sparsely distributed around the neural tube. The embryos from group 2 had an enlarged and dilated ventricle and winding and elongate outflow tract in which regurgitant blood flow was observed, whereas none in controls. Furthermore, two of the embryos had a partial pericardial defect. A continuous N-CAM immunopositive chain from the neural tube to the heart was clearly seen, though thin when compared with controls. No morphological and circulatory difference was seen between embryos from group 3 and controls.These results suggested that bis-diamine may disturb normal development and migration of cardiac neural crest or mesenchymal cells to induce various cardiovascular anomalies depending on the developmental stage.