caa a22 4500 477095283 CHVBK 20180405111525.0 cr unu---uuuuu 170330e19960601xx s 000 0 eng 10.1007/BF00187927 doi (NATIONALLICENCE)springer-10.1007/BF00187927 Development of myocardial fiber organization in the rat heart [Elektronische Daten] [Arnold Wenink, Michiel Knaapen, Benno Vrolijk, Jannetje Van Groningen] Confocal laser-scanning microscopy of phalloidine-stained actin fibers is a relatively new tool for studying the development of myocardial fiber organization. It seems to show orientation of myocytes in rather early embryonic stages. To further evaluate the differentiation of the myocardium, this technique was compared with transmission electron microscopy in rat embryos aged between 11 and 18 days. Although the confocal images of actin filament patterns pointed to early myocyte orientation, the electron micrographs revealed that even at 17 days the ventricular myocardium was far from mature. Myofibrils never completely filled the myocytes, and lack of organization was the rule rather than the exception. The organized structure as revealed by confocal microscopy was based on cell-to-cell continuity, whereas electron microscopy showed crossing and disarray within individual myocytes. Exceptions were in the ventricular trabeculations, which showed precocious myofiber differentiation. The trabeculations probably support ventricular systole in those stages in which the free walls do not yet provide efficient contractions. The other exception was the wall of the outflow tract, which showed well-oriented myofibrils from early stages onwards. Apparently, the outflow tract has a different function in these stages. The differences found between confocal microscopy and electron microscopy suggest that some caution is indicated in the interpretation of fluorescent images of relatively low magnification. Springer-Verlag, 1996 Actin nationallicence Myofibrils nationallicence Confocal laser scanning microscopy nationallicence Transmission electron microscopy nationallicence Wenink Arnold Department of Anatomy and Embryology, University of Leiden, P.O. Box 9602, RC-2300, Leiden, The Netherlands aut Knaapen Michiel Department of Anatomy and Embryology, University of Leiden, P.O. Box 9602, RC-2300, Leiden, The Netherlands aut Vrolijk Benno Department of Anatomy and Embryology, University of Leiden, P.O. Box 9602, RC-2300, Leiden, The Netherlands aut Van Groningen Jannetje Department of Anatomy and Embryology, University of Leiden, P.O. Box 9602, RC-2300, Leiden, The Netherlands aut Anatomy and Embryology Springer-Verlag 193/6(1996-06-01), 559-567 0340-2061 193:6<559 1996 193 429 https://doi.org/10.1007/BF00187927 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/BF00187927 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Wenink Arnold Department of Anatomy and Embryology, University of Leiden, P.O. Box 9602, RC-2300, Leiden, The Netherlands aut NATIONALLICENCE 700 1- Knaapen Michiel Department of Anatomy and Embryology, University of Leiden, P.O. Box 9602, RC-2300, Leiden, The Netherlands aut NATIONALLICENCE 700 1- Vrolijk Benno Department of Anatomy and Embryology, University of Leiden, P.O. Box 9602, RC-2300, Leiden, The Netherlands aut NATIONALLICENCE 700 1- Van Groningen Jannetje Department of Anatomy and Embryology, University of Leiden, P.O. Box 9602, RC-2300, Leiden, The Netherlands aut NATIONALLICENCE 773 0- Anatomy and Embryology Springer-Verlag 193/6(1996-06-01), 559-567 0340-2061 193:6<559 1996 193 429 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer