caa a22 4500 477119468 CHVBK 20180405111632.0 cr unu---uuuuu 170330e19960301xx s 000 0 eng 10.1007/BF00240054 doi (NATIONALLICENCE)springer-10.1007/BF00240054 HSP25 in isolated perfused rat hearts: Localization and response to hyperthermia [Elektronische Daten] [Brigitte Hoch, Gudrun Lutsch, Wolfgang-Peter Schlegel, Joachim Stahl, Gerd Wallukat, Sabine Bartel, Ernst-Georg Krause, Rainer Benndorf, Peter Karczewski] Recent investigations concentrate on the correlation between the myocardial expression of the inducible 70-kDa heat shock protein (HSP70i) by different stress conditions and its possible protective effects. Only few studies have focused on the involvement of small heat shock proteins in this process. We analyzed the location of the small heat shock protein HSP25 in isolated cardiomyocytes as well as its location and induction in isolated perfused hearts of rats. By immunofluorescence microscopy HSP25 was found to colocalize with actin in the I-band of myofibrils in cardiomyocytes of isolated perfused hearts as well as in isolated neonatal and adult cardiomyocytes. Hyperthermic perfusion of isolated hearts for 45 min resulted in modulation of different parameters of heart function and in induction of HSP25 and HSP70i. Temperatures higher than 43°C (44-46°C) were lethal with respect to the contractile function of the hearts. Compared to control hearts perfused at 37°C, significant increases during hyperthermic perfusion at 42°C and 43°C were obtained for heart rate, contraction velocity and relaxation velocity. In response to hyperthermia at 43°C and after subsequent normothermic perfusion for 135 min at 37°C, left ventricular pressure, contraction velocity and relaxation velocity remained significantly elevated. However, heart rate returned to control values immediately after the period of heat treatment. HSP25 is constitutively expressed even in normothermic perfused hearts as shown by Western blotting. Hyperthermia increased the content of HSP25 only in the left ventricular tissue. In contrast, HSP70i was strongly induced in all analyzed parts of the myocardium (left ventricle, right ventricle, septum). Our findings suggest a differential regulation of HSP25 and HSP70i expression in response to hyperthermia in isolated perfused hearts. The constitutively expressed HSP25 seems to be located adjacent to the myofibrils which implies a specific role of this protein even under unstressed conditions for the contractile function of the myocardium. Kluwer Academic Publishers, 1996 stress protein induction nationallicence HSP25 nationallicence intracellular location nationallicence isolated perfused heart nationallicence hyperthermia nationallicence contractile function nationallicence Hoch Brigitte Max Delbrück Centre for Molecular Medicine, Berlin-Buch, Germany aut Lutsch Gudrun Max Delbrück Centre for Molecular Medicine, Berlin-Buch, Germany aut Schlegel Wolfgang-Peter Max Delbrück Centre for Molecular Medicine, Berlin-Buch, Germany aut Stahl Joachim Max Delbrück Centre for Molecular Medicine, Berlin-Buch, Germany aut Wallukat Gerd Max Delbrück Centre for Molecular Medicine, Berlin-Buch, Germany aut Bartel Sabine Max Delbrück Centre for Molecular Medicine, Berlin-Buch, Germany aut Krause Ernst-Georg Max Delbrück Centre for Molecular Medicine, Berlin-Buch, Germany aut Benndorf Rainer Max Delbrück Centre for Molecular Medicine, Berlin-Buch, Germany aut Karczewski Peter Max Delbrück Centre for Molecular Medicine, Berlin-Buch, Germany aut Molecular and Cellular Biochemistry Kluwer Academic Publishers; http://www.wkap.nl 160-161/1(1996-03-01), 231-239 0300-8177 160-161:1<231 1996 160-161 11010 https://doi.org/10.1007/BF00240054 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/BF00240054 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Hoch Brigitte Max Delbrück Centre for Molecular Medicine, Berlin-Buch, Germany aut NATIONALLICENCE 700 1- Lutsch Gudrun Max Delbrück Centre for Molecular Medicine, Berlin-Buch, Germany aut NATIONALLICENCE 700 1- Schlegel Wolfgang-Peter Max Delbrück Centre for Molecular Medicine, Berlin-Buch, Germany aut NATIONALLICENCE 700 1- Stahl Joachim Max Delbrück Centre for Molecular Medicine, Berlin-Buch, Germany aut NATIONALLICENCE 700 1- Wallukat Gerd Max Delbrück Centre for Molecular Medicine, Berlin-Buch, Germany aut NATIONALLICENCE 700 1- Bartel Sabine Max Delbrück Centre for Molecular Medicine, Berlin-Buch, Germany aut NATIONALLICENCE 700 1- Krause Ernst-Georg Max Delbrück Centre for Molecular Medicine, Berlin-Buch, Germany aut NATIONALLICENCE 700 1- Benndorf Rainer Max Delbrück Centre for Molecular Medicine, Berlin-Buch, Germany aut NATIONALLICENCE 700 1- Karczewski Peter Max Delbrück Centre for Molecular Medicine, Berlin-Buch, Germany aut NATIONALLICENCE 773 0- Molecular and Cellular Biochemistry Kluwer Academic Publishers; http://www.wkap.nl 160-161/1(1996-03-01), 231-239 0300-8177 160-161:1<231 1996 160-161 11010 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer