Molecular biological analysis of cardiac effect of high temperature in rats.

Authors:
Address: Department of Forensic Medicine and Sciences, Mie University Graduate School of Medicine, 2-174 Edobashi, Tsu City, Mie, Japan. yasnak@doc.medic.mie-u.ac.jp
Journal:

Publication:

abstract

The aim of this study was to investigate direct effects of heat exposure on the heart Molecular-biologically and pathohistologically, using rats exposed to high temperatures. The mRNA expression of natriuretic peptide type A (Nppa), natriuretic peptide type B (Nppb), actin alpha 1 skeletal muscle (Acta1), myosin heavy polypeptide 6 cardiac muscle alpha (Myh6) and myosin heavy polypeptide 7 cardiac muscle alpha (Myh7) was determined in the hearts of the rats. Whereas the expression of Nppa and Nppb rapidly increased immediately after the heat exposure, the expression of Acta1 was gradually reduced, which indicated cardiac overload. Moreover, the expression of Myh6 and Myh7 in the heart increased 4h after the heat exposure, which suggested the involvement of a compensatory mechanism. Immunohistochemical staining with anti-fibronectin antibody showed that positive cardiomyocytes could be detected sparsely 4h after the heat exposure, and they could be clearly observed 8h after the heat exposure. Our results showed that hyperthermia causes myocardial damage shortly after the exposure to heat and that the ventricle was more vulnerable to hyperthermia-induced damage than the atrium. Cardiac dysfunction may be induced not only by hypercytokinemia but also by the direct effect of heat exposure at the early period of heat stroke, which may be one of the mechanisms by which heat causes death. Elucidating the mechanism of death from heat stroke could lead to not only diagnostic improvement but also the prevention of death from heat stroke.

Related Articles
Final Report on Carcinogens Background Document for Formaldehyde.
Rep Carcinog Backgr Doc. 2010
Final Report on Carcinogens Background Document for Formaldehyde.
National Toxicology Program. Rep Carcinog Backgr Doc. 2010 Jan; (10-5981):i-512.
Final Report on Carcinogens Background Document for Styrene.
Rep Carcinog Backgr Doc. 2008
Final Report on Carcinogens Background Document for Styrene.
National Toxicology Program. Rep Carcinog Backgr Doc. 2008 Sep; (8-5978):i-398.
[Effect of miRNA-199a on rat cardiac hypertrophy].
Zhonghua Xin Xue Guan Bing Za ...
[Effect of miRNA-199a on rat cardiac hypertrophy].
Xu XD, Song XW, Jing Q, Qin YW. Zhonghua Xin Xue Guan Bing Za Zhi. 2011 May; 39(5):446-50.
Review Winner of the Lund Science Award 1992. Thermosensitization induced by step-down heating. A review on heat-induced sensitization to hyperthermia alone or hyperthermia combined with radiation.
Int J Hyperthermia. 1992
Review Winner of the Lund Science Award 1992. Thermosensitization induced by step-down heating. A review on heat-induced sensitization to hyperthermia alone or hyperthermia combined with radiation.
Lindegaard JC. Int J Hyperthermia. 1992 Sep-Oct; 8(5):561-86.
Review Molecular adaptation to pressure overload in human and rat hearts.
J Mol Cell Cardiol. 1989
Review Molecular adaptation to pressure overload in human and rat hearts.
Yazaki Y, Tsuchimochi H, Kurabayashi M, Komuro I. J Mol Cell Cardiol. 1989 Dec; 21 Suppl 5:91-101.

To top • Home

TraveldoctorOnline 2001 • Disclaimer • webmaster

The contents within traveldoctoronline are presented only for informational purposes and cannot substitute for professional health care or any other medical treatment.All users of this website with health problems should be oblige always to consult their medical doctor before starting any treatment.