Ultrastructural characteristics of the formation and development of the intercalated disc in the rat left and right work-ing ventricular myocardium on the postnatal ontogenetic stages.

Authors

  • N. S. Petruk ДЗ «Дніпропетровська медична академія МОЗ України», Ukraine

DOI:

https://doi.org/10.26641/1997-9665.2013.3.94-100

Keywords:

ventricular myocardium, rats, postnatal ontogenesis, ultrastructure of the intercalated disc, convolution index, annular gap junction

Abstract

Background. Maintenance of the normal distribution of intercellular contacts between cardiomyocytes and preservation of the correct geometry of the intercalated disc are essential conditions for the proper functioning of the heart. Objective. To provide complex ultrastructural evaluation of the mechanism of formation and development of the intercalated disc in rat ventricular myocardium on postnatal stages of development. Methods. Rats at the age of 1, 3, 7, 14, 30 days after birth and mature individuals were used as an object. Transmission electron microscopy, morphometric and statistical methods were applied. In particular, the convolution index was evaluated to characterize quantitative changes of the dynamics of configuration of intercalated disc. Results. It was found that the redistribution of adherens junctions from the lateral surface of cardiomyocytes occurs most rapidly from 3rd to 14th days after birth. The gap junctions trimming occurs due to their internalization with subsequent formation of the annular gap junction profile in the sarcoplasm; these profiles are inserted into the intercalated disc at the last turn. The process of complication of the geometry of intercalated disc is accompanied by the consistent increase of convolution index in the mature myocardium of the left and right ventricles up to 2,46±0,17 and 1,94±0,14, respectively. The predominance of the convolution index in the left ventricle over the levels in the right ventricle was the most prominent on the 14th day of postnatal development (38,1%; p<0,05) and in the mature myocardium – 26,8% (p<0,05). Conclusion. As the result of physiological hypertrophy and adaptive remodeling of cardiomyocyte in the postnatal rat cardiogenesis redistribution of diffusely located intercellular junctions from the periphery to the terminal areas of the cell occurs. The formation of a definitive pattern of distribution of intercellular junctions is completed at the puberty.

References

  1. Hesketh GG, Shah MH, Halperin VL, Cooke CA, Akar FG, Yen TE, Kass DA, Machamer CE, Van Eyk JE, Tomaselli GF. Ultrastructure and regulation of lateralized connexin43 in the failing heart. Circ Res. 2010 Apr 2;106(6):1153-63. doi: 10.1161/CIRCRESAHA.108.182147. Epub 2010 Feb 18. Cited in: PubMed; PMID: 20167932; PMCID: PMC2896878.
  2. Hoyt RH, Cohen ML, Saffitz JE. Distribution and three-dimensional structure of intercellular junctions in canine myocardium. Circ Res. 1989 Mar;64(3):563-74. Cited in: PubMed; PMID: 2645060.
  3. Oosthoek PW, van Kempen MJ, Wessels A, Lamers WH, Moorman AFM. Distribution of the cardiac gap junction protein, connexin 43, in the neonatal and adult human heart. In: Marechal G, Carraro U, eds. Muscle and Motility, Volume 2: Proceedings of XIXth European Conference in Brussels. Andover, Hants, UK: Intercept Ltd; 1994:85-90.
  4. Miyamoto T, Zhang L, Sekiguchi A, Hadama T, Shimada T. Structural differences in the cytoarchitecture and intercalated discs between the working myocardium and conduction system in the human heart. Heart Vessels. 2002 Sep;16(6):232-40. Cited in: Pub-Med; PMID: 12382032.
  5. Spach MS. Changes in the topology of gap junctions as an adaptive structural response of the myocardium. Circulation. 1994 Aug;90(2):1103-6. Cited in: PubMed; PMID: 8044925.
  6. Palatinus JA, Rhett JM, Gourdie RG. The connexin43 carboxyl terminus and cardiac gap junction organization. Biochim Biophys Acta. 2012 Aug;1818(8):1831-43. doi: 10.1016/j.bbamem.2011.08.006. Epub 2011 Aug 9. Cited in: PubMed; PMID: 21856279; PMCID: PMC3244566.
  7. Legato MJ. Cellular mechanisms of normal growth in the mammalian heart. I. Qualitative and quantitative features of ventricular architecture in the dog from birth to five months of age. Circ Res. 1979 Feb;44(2):250-62. Cited in: PubMed; PMID: 761307.
  8. Collins TJ. ImageJ for microscopy. Biotechniques. 2007 Jul;43(1 Suppl):25-30. Cited in: PubMed; PMID: 17936939.

How to Cite

Petruk, N. S. (2013). Ultrastructural characteristics of the formation and development of the intercalated disc in the rat left and right work-ing ventricular myocardium on the postnatal ontogenetic stages. Морфологія / Morphologia / Morfologìâ, 7(3), 94–100. https://doi.org/10.26641/1997-9665.2013.3.94-100

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