Effects of maternal diabetes on early embryogenesis. Alterations in morphogenesis produced by the ketone body, B-hydroxybutyrate.
The present study used the whole embryo culture technique to determine the effects of the ketone body, B-hydroxybutyrate (B-OHB), on organogenesis in mouse embryos. Embryos of two stages (3-4 and 5-6 somites) were exposed for 24 h to a racemic mixture of D-L B-OHB at levels of 8, 16, or 32 mM/L. An abnormal pattern of development resulted, consisting of growth reduction and inhibition or delay of neural tube closure in the cranial and/or caudal regions of the embryo. These effects were dose- and age-dependent, such that younger embryos were more frequently affected than older ones, and increasing doses produced a higher rate of malformation. Growth reduction as evidenced by embryonic protein showed similar relationships. Histologic analysis of embryos exposed to 32 mM/L B-OHB for 24 h revealed numerous cytoplasmic "vacuoles" widespread throughout the neuroepithelium, mesenchyme, and ectoderm. Ultrastructurally, these "vacuoles" proved to be mitochondria that had undergone high-amplitude swelling with a loss of matrix density and few identifiable cristae. No other consistent ultrastructural changes were noted, and the mitochondria of control tissues displayed a typical orthodox configuration. While this study does not conclusively limit the effects to the D-form of B-OHB, possible relationships exist between the ultrastructural alterations, ketone body metabolism, and abnormal morphogenesis.
D020155:3-Hydroxybutyric Acid; D000818:Animals; D004305:Dose-Response Relationship, Drug; D004622:Embryo, Mammalian / Q000187:drug effects* / Q000473:pathology / Q000648:ultrastructure; D005260:Female; D005865:Gestational Age; D006885:Hydroxybutyrates / Q000494:pharmacology*; D008648:Mesoderm / Q000187:drug effects / Q000648:ultrastructure; D051379:Mice; D009436:Neural Tube Defects / Q000139:chemically induced*; D009924:Organ Culture Techniques; D011247:Pregnancy; D011254:Pregnancy in Diabetics / Q000196:embryology*
D006885:Hydroxybutyrates; D020155:3-Hydroxybutyric Acid