[Quantitative analysis of the ultrastructural changes in the organoids of the visual cells of chick embryos exposed to actinomycin D].

A quantitative analysis of ultrastructural changes in organelles of retina differentiating photoreceptors in 10, 11, 12, and 13 day old chick embryos in the presence of Actinomycin was done. Within 10-13th days of development, with the formation of ellipsoid and paraboloid photoreceptors, there is an increase in the areas of mitochondria and endoplasmic reticulum, and in the number of polyribosomes. Actinomycin injection to embryos sharply reduces some cell parameters: single mitochondrial area, areas of endoplasmic reticulum elements, their length and diameters. In addition to disintegration of polyribosomal complexes was noticed in the cell cytoplasm beginning from 1 hour to 24 hours of inhibitor action. A delay in formation of ellipsoid and paraboloid occurred, especially in membrane discs of the external segment of photoreceptor.