Effect of vitamin A acetate on selected morphogenetic systems of the chick embryo
Kosar, K.
Folia Morphologica 34(1): 59-68
1986
ISSN/ISBN: 0015-5640 PMID: 3699639 Document Number: 273254
The effects of vitamin A acetate on morphogenetic systems of the chick embryo were studied by means of the CHEST (CHick Embryotoxicity Screening Test). The subgerminal administration of doses of 0.03 .mu.g and over induced retardation of growth of the caudal morphogenetic system, including abnormal extraembryonic vasculogenesis and the formation of numerous foci of haemorrhage in the caudal part of the trunk. The administration of single effective doses of vitamin A acetate-subgerminally on the second day and intraamniotically on the third and fourth-produced a biphasic effect. The nonspecific, generally cytotoxic effect in lower developmental stages (day 2) was succeeded on the fourth day by a specific effect, when the incidence of embryotoxic manifestation of the test substance was significantly higher. The commonest defects diagnosed in the surviving embryos on day 8 were body wall defects, defects of the interventricular septum of the heart and occasionally malformations of the face (cleft beak), the limbs and the trunk. The target tissues are virtually the same as those in mammalian embryos. The time distribution of the diagnosed morphological defects is indicative of increasing sensitivity of the morphogenetic systems with advancing development, not unlike sensitivity to the steroid hormones. It can be assumed that the effect of vitamin A acetate in the phase of the critical developmental periods of most of the morphogenetic systems might reflect the progressive development of specific binding proteins in the cell populations of the target embryonic morphogenetic systems.