Summary
Intermittent high altitude (IHA) hypoxia (7000 m) increased the wet weight of the right ventricular myocardium of 30-day-old rats after two 4 h/day exposures. During the same period the number of DNA-synthesizing nuclei of both muscle and non-muscle cell types increased proportionally. After 4 such exposures to hypoxia the number of3H-thymidine-labelled nuclei in both cell types increased further. In addition, the number of labelled nuclei increased significantly in the yet un-enlarged left ventricle.
While there was no difference in the number of DNA-synthesizing cells between the right and left ventricles in control animals, a significant increase in the number of cells involved in DNA synthesis in the right ventricle was found in both groups of animals exposed to IHA hypoxia.
These results show that DNA synthesis in myonuclei of the ventricular myocardium can be stimulated in 30-day-old rats, i.e. at the very end of the weaning period.
Similar content being viewed by others
References
Badeer, H.S.: Development of cardiomegaly: A unifying hypothesis explaining the growth of muscle fibres, blood vessels and collagen of the heart. Cardiology57, 247–261 (1972)
Bishop, S.P., Meisen, L.R.: Myocardial necrosis, fibrosis, and DNA synthesis in experimental cardiac hypertrophy induced by sudden pressure overload. Clin. Res.39, 238–245 (1976)
Claycomb, C.W.: Poly/adenosin diphosphate ribose/polymerase activity and nicotinamide adenine dinucleotide in differentiating cardiac muscle. Biochem. J.154, 387–393 (1976)
Crane, W.A.J., Dutta, L.P.: The utilization of tritiated thymidine for deoxyribonucleic acid synthesis by the lesion of experimental hypertension in rats. J. Path. Bact.86, 83–97 (1963)
Fulton, R.M., Hutchinson, E.C., Jones, A.M.: Ventricular weight in cardiac hypertrophy. Brit. Heart J.14, 413–420 (1952)
Grove, D., Nair, K.G., Zak, R.: Biochemical correlates of cardiac hypertrophy. III. Changes in DNA content: Relative contributions of polyploidy and mitotic activity. Circulation Res.25, 463–471 (1969)
Hollenberg, M., Honbo, N., Samorodin, A.J.: Effects of hypoxia on cardiac growth in neonatal rats. Amer. J. Physiol.231, 1445–1450 (1976)
Klinge, O.: Karyokinese und Kernmuster in Herzmuskel wachsender Ratte. Virchows Arch. Abt. B Zellpath.6, 206–219 (1970)
Klinge, O., Stöcker, E.: Die DNA-Synthese im Rattenherzen als Funktion des Lebensalters. Autoradiographische Untersuchungen mit3H-Thymidin. Experientia24, 167–168 (1968)
Mandache, E., Unge, G., Ljunquist, A.: Myocardial blood capillary reaction in various forms of cardiac hypertrophy. An electron microscopical investigation in the rat. Virchows Arch. Abt. A Path. Anat.11, 97–110 (1972)
Mareš, V., Schultze, B., Maurer, W.: Stability of DNA in Purkinje cell nuclei of the mouse. An autoradiographic study. J. Cell. Biol.63, 665–674 (1974)
Meerson, F.Z., Alekhina, G.M.: The effect of contractile activity of the heart muscle cells on the DNA synthesis in the interstitial cells of myocardium. Dokl. Akad. Nauk SSSR173, 1222–1225 (1967)
Meerson, F.Z.: Role of the synthesis of nucleic acids and proteins in the adaptation of the organism to altitude hypoxia. Cardiology56, 173–187 (1971)
Morkin, E., Ashford, T.P.: Myocardial DNA synthesis in experimental cardiac hypertrophy. Amer. J. Physiol.215, 1409–1413 (1968)
Neffgen, F., Korecký, B.: Cellular hyperplasia and hypertrophy in cardiomegalies induced by anaemia in young and adult rats. Circulation Res.30, 104–113 (1972)
Poupa, O., Ošfádal, B.: Experimental cardiomegalies and cardiomegalies in free-living animals. Ann. N. Y. Acad. Sci.156, 445–468 (1969)
Rakusan, K., Poupa, O.: Differences in capillary supply of hypertrophied and hyperplastic hearts. Cardiologia49, 293–298 (1966)
Rumyantsev, P.P.: A morphological and autographical study of the pecularities of differentiation rate, DNA synthesis and nuclear division in the embryonal and postnatal histogenesis of cardiac muscles of white rats. Folia histochem.1, 463–471 (1963)
Rumyantsev, P.P.: DNA synthesis and mitosis in atrial myocytes of rats with aortal stenosis. Experientia26, 773–774 (1970)
Sandritter, W., Adler, C.P.: Numerical hyperplasia in human heart hypertrophy. Experientia27, 1435–1437 (1971)
Sasaki, R., Toshiaki, M., Yamagata, S.: Mitosis of heart muscle cells in normal rats. Tohoku J. Exp. Med.96, 405–411 (1968)
Sasaki, R., Morishita, T., Ischikawa, S., Yamagata, S.: Autoradiographic studies and mitosis of heart muscle cells in experimental cardiac hypertrophy. Tohoku J. Exp. Med.102, 159–167 (1970)
Wachtlová, M.: Different types of cardiomegaly and its blood supply. Folia Fac. Med. Univ. Comen.10, suppl. 89–100 (1972)
Wegner, G., Mölbert, E.: Das Verhalten des Myokards bei der experimentellen supravalvulären Aortenstenose. Autoradiographische und elektronenmikroskopische Untersuchungen an Rattenherzen. Virchows Arch.341, 54–63 (1966)
Zak, R.: Development and proliferative capacity of cardiac muscle cells. Circulation Res.134-135, suppl. 11–17-11–27(1974)
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Wachtlová, M., Mares, V. & Ošťádal, B. DNA synthesis in the ventricular myocardium of young rats exposed to intermittent high altitude (IHA) hypoxia. Virchows Arch. B Cell Path. 24, 335–342 (1977). https://doi.org/10.1007/BF02889289
Received:
Issue Date:
DOI: https://doi.org/10.1007/BF02889289