Back
Acta Physiologica 2009; Volume 195, Supplement 669
The 88th Annual Meeting of The German Physiological Society
3/22/2009-3/25/2009
Giessen, Germany
ENDURANCE TRAINING IN HETEROZYGOUS ILK-DEFICIENT MICE INDUCES A HYPERTROPHIC CARDIOMYOPATHY
Abstract number: P385
Brixius1 K., Wang2 H.-V., Kopitzke1 L., Malan3 D., Ghanem4 A., Tiemann5 K.-D., Thievessen2 I., Fleischmann3 B., Bloch1 W.
1Dept. of Molecular and Cellular Sport Medicine, Institute for Cardiovascular Research and Sport Medicine, Kln
2Dept. of Molecular Medicine, MPI for Biochemistry, Martinsried
3Life and Brain, Bonn
4Dept. of Cardiology, Medical University of Bonn, Bonn
5Dept. of Cardiology, Medical University of Bonn, Bonn
The integrin-linked kinase belongs to a focal adhesion complex which connects the cytoskeleton with the extracellular matrix proteins. Only recently, we have shown that ILK-deficiency alters skeletal muscle function as well as its adaptation towards a running exercise in hetreozygous transgenic mice. In the present study we investigated alterations in cardiac morphology(heart-to-body weight ratio, cardiomyocyte diameter, capillarisation), exercise-induced hypertrophic signalling (Akt/PKB, immunohistochemical detection), eNOS-regulation and function (echocardiography) in the hearts of heterozygous ILK-deficient mice (ILKKO) in comparison to wild-type mice (WT) after a 4 weeks-running exercise (5 days a week, 60 min., 18 m/s, declination 10°).
Heart-to-body weight ratio was slightly but not significantly increased in 5 months-old ILK KO animals (6.40.4) compared to WT (5.90.3). However, the mean diameter of the cardiomyocytes of ILK KO mice (19.14.5 mm) was significantly increased compared to WT (18.13.5 mm). The variability in the cardiomyocyte diameter was more pronounced in ILKKO (14.8 – 22.5 mm) compared to WT (15.2 – 21.7 mm). Despite the increase in the cardiomyocyte diameter, the number of capillaries per cardiomyocytes was similar in ILKKO (3.60.9) and WT (3.70.8). Phosphorylation of the Akt/PKB was significantly reduced in the ILKKO (10.33.5 densitometric units, du) compared to the WT (11.73.7 du) animals. In the ILKO animals a dysorganisation of the co-localisation of the eNOS/caveolin-complex was observed in some cardiomyocytes. However, no alterations of eNOS-phosphorylation at serine 1177 were detected. At older age (9 months), heart-to-body weight ratio was significantly increased in ILK KO (7.00.7) mice compared to WT (4.90.4) after the same exercise performance. These alterations were paralleled by a decrease in cardiac ejection fraction and a slight increase in end-diastolic diameter (90.416.6 ml vs. 73.411.9 ml) indicating the development of a hypertrophic dilated cardiac phenotype.
Conclusions:
The present study indicates that ILK may play a role for the exercise-induced adaptation of cardiac muscle, especially at older age.
To cite this abstract, please use the following information:
Acta Physiologica 2009; Volume 195, Supplement 669 :P385