Development of Rat Embryos Cultured in Glucose-Deficient Media

Embryo-culture techniques were used to study the effects of exposure to glucose-deficient culture media on rat embryos during organogenesis. Embryos and their extraembryonic membranes (explants) were cultured either in control media or in media with low or very low glucose concentrations. At the start of the culture the glucose concentrations were 8.4 ± 0.57, 4.5 ± 0.10, and 3.5 ± 0.07 mM. During the cultures, the explants progressively depleted the glucose in the medium until, after 48 h, the glucose concentrations were reduced to 1.1 ± 0.18, 0.4 ± 0.13, and 0.3 ± 0.02 mM, respectively. At glucose concentrations <2.5 mM, the rate of glucose uptake by the explants progressively decreased, and embryonic growth and differentiation became increasingly retarded. After 48 h in glucose-deficient culture media, embryos had smaller crown-rump lengths, lower protein contents, and fewer somites than embryos from the control media (P < .001). Most of the embryos exposed to the lower glucose concentrations also had severe dysmorphic lesions, especially of the head and branchial arches. The deleterious effects of exposure to low concentrations of glucose on embryonic development appeared not to be reversible. Embryos cultured for 24 h in media with a low concentration of glucose followed by 24 h in control medium grew and developed just as poorly as those cultured for the entire 48 h in the glucose-deficient media.