title: Effects of cyproheptadine on the rat yolk sac membrane and embryonic development in vitro.
abstract: Electron-microscopic examinations of rat embryonic yolk sacs treated in vitro with 1.5 X 10(-5) M cyproheptadine showed proliferation of the lysosomal structures; other organelles remained unaffected, and also overall yolk-sac growth and vascularization were comparable to non-treated samples. Radioactive measurements with 125I-labelled albumin showed that yolk sacs and embryos of the cyproheptadine-treated group incorporated less radioactivity than the controls. Embryos inside the yolk sacs, treated either for 24 or 48 h, were severely retarded in growth and differentiation (approximately 50% of the controls). It is suggested that the specific action of cyproheptadine on yolk-sac lysosomal structures, combined with reduced macromolecular transport, is the cause of inhibited embryonic development.
mesh_terms: D000818:Animals; D046508:Culture Techniques / Q000379:methods; D003533:Cyproheptadine / Q000633:toxicity*; D004622:Embryo, Mammalian / Q000187:drug effects; D005260:Female; D008854:Microscopy, Electron; D011247:Pregnancy; D051381:Rats; D013723:Teratogens; D015017:Yolk Sac / Q000187:drug effects* / Q000473:pathology / Q000648:ultrastructure
chemical_list: D013723:Teratogens; D003533:Cyproheptadine