Diabetes Mellitus and Teratogenicity - Embryotoxic Effects of Insulin-induced Hypoglycemic Serum during Early Organogenesis in Rat Embryo Culture

我们已经证明，在器官发生早期暴露于胰岛素诱导的低血糖血清会对大鼠胚胎培养中的胚胎发育产生不利影响，这些影响是通过中断糖酵解通量介导的，糖酵解通量是胚胎这一阶段的主要途径（Diabetologia 30: 791, 1987）。进一步的实验是为了确定在关键时期短暂暴露于低血糖血清是否对胚胎发生有不利影响。妊娠9.5天的早期头襞期大鼠胚胎体外培养48小时，直至神经管闭合。基础培养基由含有1.2mg/ml葡萄糖（75%正常大鼠血清）的对照培养基和等渗添加6.0mg/ml葡萄糖的高血糖培养基组成，其中未引起畸形病变。降糖培养基（0.4mg/ml葡萄糖）为腹腔注射胰岛素的大鼠血清。在基础培养的早期神经管形成过程中，植入后胚胎在妊娠第10.3天更短（1小时）暴露于胰岛素诱导的低血糖血清中。在对照培养基培养期间，在低血糖培养基中短暂暴露1小时，胚胎出现轻度生长迟缓[冠臀比（C-R） 3.24 <正负> 0.05 VS 3.46 <正负> 0.05mm， P<0.01；（27.3 <正负> 0.4 VS 28.2 <正负> 0.1，P<0.05）和小但显著的畸形病变（7%的神经孔开放，13%的小脑畸形，11%的骨骼异常）。高血糖培养基中添加亚致畸剂量的葡萄糖（6.0mg/ml），在低血糖血清中培养1小时，可导致较大的生长迟缓（C-R 3.12 <正负> 0.03 VS 3.35 <正负> 0.06，P<0.01；体数26.9 <正负> 0.02 VS 28.27 <正负> 0.18，P<0.01）和明显的畸形病变（24%神经孔开放，25%小脑，14%骨骼异常，10%眼睛异常，5%心脏异常）。这些结果表明，即使是短暂的低血糖也会对胚胎发育的关键时期产生不利影响，并且当胚胎在hype Less中培养时，这种影响会增强

We have shown that exposure to insulin induced-hypoglycemic serum during early phase of organogenesis can adversely affect the embryonic development in rat embryo culture and these effects are mediated through interruption of glycolytic flux that constitutes principal pathway at this stage of embryo (Diabetologia 30: 791, 1987). Further experiments were performed to determine whether or not even brief exposure to hypoglycemic serum during the critical periods has adverse effects on embryogenesis. Rat embryos of 9.5 days of gestation at early head-fold stage were grown in vitro for 48-hr until neural tube closure. Basal culture media consisted of control media containing 1.2mg/ml glucose (75% normal rat serum) and hyperglycemic media supplemented isosmotically with 6.0mg/ml glucose to control media, in which dysmorphogenic lesions were not elicited. Hypoglycemic media (0.4mg/ml glucose) were sera that were obtained from rats given insulin intraperitoneally. Postimplantation embryos were … More briefly (for 1-hr) exposed to the insulin-induced hypoglycemic serum at day 10.3 of gestation in early neural tube formation during the basal culture. On brief exposure to hypoglycemic media for 1-hr during culture with control media, embryos showed minor growth retardation [crown-rump (C-R) 3.24 <plus-minus> 0.05 VS 3.46 <plus-minus> 0.05mm, P<0.01; somite number 27.3 <plus-minus> 0.4 VS 28.2 <plus-minus> 0.1, P<0.05] and small but significant dysmorphogenic lesions (7% open neural pore, 13% microencephaly, 11% skeltal abnormality). Exposure to hypoglycemic serum for 1h during the culture with hyperglycemic media supplemented with subteratogenic dosis of glucose (6.0mg/ml) resulted in greater growth retardation (C-R 3.12 <plus-minus> 0.03 VS 3.35 <plus-minus> 0.06, P<0.01; somite number 26.9 <plus-minus> 0.02 VS 28.27 <plus-minus> 0.18, P<0.01) and marked dysmorphogenic lesions (24% open neural pore, 25% microencepaly, 14% skeltal abnormality, 10% eye abnormality, 5% heart abnormality). These results indicate that even brief hypoglycemia can adversely affect the embryogenesis at critical developing periods and these effects are enhanced when embryogs were cultured in hype Less