caa a22 4500 467941696 CHVBK 20180406153014.0 cr unu---uuuuu 170328e20060801xx s 000 0 eng 10.1007/s00421-006-0239-0 doi (NATIONALLICENCE)springer-10.1007/s00421-006-0239-0 Microcirculation in rat soleus muscle after eccentric exercise: the effect of nifedipine [Elektronische Daten] [S. Heap, G. Fulgenzi, O. Hudlicka] This paper explores the role of the calcium entry blocker nifedipine in the explanation of eccentric exercise-induced fibre damage by changes in skeletal muscle microcirculation. Eccentric exercise (EE) was induced by indirect stimulation of rat soleus muscle in its lengthening phase during cycling. Muscle damage was assessed by histology, electron microscopy and muscle tension 48h later. Diameters of arterioles and venules, their response to dilator and constrictor stimuli and pattern of capillary flow were measured in epiiluminated muscles using intravital microscopy. Tetanic tension developed by EE muscles was lower (8.60±1.02, means±SEM, n=8Ng−1 wet weight compared to 12.25±0.56 in controls, P<0.01). Electron microscopy showed changes similar to those in muscles exposed to EE by downhill running (Z line streaming, disruption of sarcolemma, swollen tubules). A total of 16% of muscle fibres were damaged, and fibre areas and interstitial space were enlarged. Capillary red blood cell flow showed tendency to a greater intermittency. Large venules were narrower, but arterioles and smaller venules had diameters similar to control muscles. Vessel dilatation to topically applied 10−4M adenosine was attenuated. Daily administration of calcium entry blocker nifedipine by gavage (2mg/kg/day in two equal doses) removed the narrowing of venules, restored the dilator response of all vessels to adenosine and increased capillary:fibre ratio. The percentage of damaged fibres decreased to 4.7 and the size of the interstitial space and fibre areas was normalized. Thus muscle damage caused by eccentric exercise was attenuated by nifedipine due to its beneficial effect on muscle microcirculation, which was impaired by eccentric exercise. Springer-Verlag, 2006 Muscle damage nationallicence Oedema nationallicence Arterioles nationallicence Venules nationallicence Dilatation nationallicence Heap S. Department of Physiology, Division of Medicine, University of Birmingham Medical School, B15 2TT, Birmingham, UK aut Fulgenzi G. Department of Molecular Pathology and Innovative Therapies, University of Marche, Ancona, Italy aut Hudlicka O. Department of Physiology, Division of Medicine, University of Birmingham Medical School, B15 2TT, Birmingham, UK aut European Journal of Applied Physiology Springer-Verlag 97/6(2006-08-01), 687-694 1439-6319 97:6<687 2006 97 421 https://doi.org/10.1007/s00421-006-0239-0 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s00421-006-0239-0 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Heap S. Department of Physiology, Division of Medicine, University of Birmingham Medical School, B15 2TT, Birmingham, UK aut NATIONALLICENCE 700 1- Fulgenzi G. Department of Molecular Pathology and Innovative Therapies, University of Marche, Ancona, Italy aut NATIONALLICENCE 700 1- Hudlicka O. Department of Physiology, Division of Medicine, University of Birmingham Medical School, B15 2TT, Birmingham, UK aut NATIONALLICENCE 773 0- European Journal of Applied Physiology Springer-Verlag 97/6(2006-08-01), 687-694 1439-6319 97:6<687 2006 97 421 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer