title: [Structure of the blood vessels of the microcirculatory bed in different organs of albino rats in neonatal period of ontogenesis].
abstract: In newborn albino rats the walls of some of the blood vessels of microcirculatory bed are not completely formed in the myocardium of left ventricle, testis, adrenal cortex and liver. Arterioles and venules are found to be few. Unformed areas of these blood vessels contain immature endotheliocytes with nucleolonemal nucleoli (3-4 (min diameter) and numerous ribosomes in the cytoplasm. In these nucleoli the Ag-NOR-proteins are forming a continuous network that unites fibrillar centers and a dense fibrillar component. In rats on postnatal day 8 the number of such endotheliocytes is significantly reduced. In animals aged 15 days the walls of all the vessels of microcirculatory bed acquire definitive structure and only mature endotheliocytes are revealed, the majority of which have annular nucleoli with corresponding one Ag-positive zone.
authors.affiliation: Department of Experimental Anatomy, Institute of Experimental Morphology of Georgian Academy of Sciences, Tbilisi, Georgia.
authors.forename: Iu R
authors.initials: IuR
authors.lastname: Arveladze
mesh_terms: D000302:Adrenal Cortex / Q000098:blood supply / Q000648:ultrastructure; D000375:Aging / Q000473:pathology*; D000818:Animals; D000831:Animals, Newborn; D002466:Cell Nucleolus / Q000648:ultrastructure; D003331:Coronary Vessels / Q000648:ultrastructure; D004730:Endothelium, Vascular / Q000648:ultrastructure*; D008099:Liver / Q000098:blood supply / Q000648:ultrastructure; D008297:Male; D008833:Microcirculation / Q000254:growth & development* / Q000648:ultrastructure; D008854:Microscopy, Electron; D051381:Rats; D013737:Testis / Q000098:blood supply / Q000648:ultrastructure