EFFECTS OF HYPOGLYCEMIA ON EARLY EMBRYOGENESIS IN RAT WHOLE-EMBRYO CULTURE SYSTEM

Objective: We investigated the effects of short- and long-term hypogly cemia on organogenesis on the rat embryo. We also assessed the effects of 1-h exposure to hypoglycemia in embryos cultured in a normoglycemi c medium (glucose, 150 mg/dl) and embryos cultured in a hyperglycemic medium (glucose, 300 mg/dl). Methods: Nine-day-old rat embryos were cu ltured in vitro for 48 h using the whole-embryo culture system of New. (6) Results: Growth retardation was observed after 48-h exposure to hy poglycemia. Embryos incubated for 24 to 48 h in the hypoglycemic mediu m showed an increased frequency of major malformations, characterized by neural lesions compared with control embryos. Embryos exposed to hy poglycemia for 1 h at 17 h of culture showed growth retardation and an increased frequency of minor malformations compared with the control. Hypoglycemia induced growth retardation and dysmorphogenesis in the e mbryos cultured in the hyperglycemic medium more than in the embryos c ultured in the normoglycemic medium. Conclusion: Hypoglycemia exerted an embryopathic effect on rat embryos during organogenesis. Embryos ex posed to hypoglycemia during the first 24 h were more vulnerable to gr owth retardation and dysmorphogenesis than those exposed later. The ef fects were enhanced by a fluctuation of glucose concentration in the c ulture medium.