Chicken embryo, vitamin

This method was applied to the determination of vitamin Bg concentration in chicken embryo livers ranging from 8 to 14 d of development [8]. 

The ascorbic acid content of the adrenal glands of chicken embryos has been studied by Case (1952), who found an appreciable increase (from 95 to 167 mg %) in the concentration of this vitamin in the gland from the 12th to the 19th day of incubation. According to observations by Perek et al. (1959), the ascorbic acid level of the gland decreases from an average value of 305 28 mg % in 3-month-old pullets to 222 19 mg % in 1-year-old hens. 

Evidence is also available that the developing chicken embryo obtains vitamin A needed for fetal development from maternal retinol-RBP complex that had been incorporated into the yolk of the egg (Heller, 1976 Abe et al., 1976 Sreekrishna and Cama, 1978). It has been found in humans that vitamin A in cord blood is present as the retinol-RBP complex (Vahlquist et al., 1975). RBP in human fetal serum, collected at the time of birth, appeared to be identical with RBP present in serum of adults (Ismadi and Olson, 1975). The extent to which cord blood RBP might represent RBP transferred from maternal to fetal circulation, compared to RBP synthesized by the term fetus, is not known. Retinol present in holo-RBP in cord blood certainly must have had a maternal origin. Information is needed about the mechanisms involved in the transport of RBP across the placenta in the developing mammalian fetus at different stages of development. 

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