Submitted to: Journal of Federation of American Societies for Experimental Biology
Publication Type: Abstract Only
Publication Acceptance Date: 12/2/2002
Publication Date: 3/14/2003
Citation: Klevay, L.M., Lukaski, H.C., Britton, S.L., Koch, L.G. 2003. Increased copper and iron in skeletal muscles of rats bred to run long distances [abstract]. Federation of American Societies for Experimental Biology Journal. 17:A1160.
Technical Abstract: Selective breeding of rats through nine generations has produced high-capacity runners (HCR) that run on a treadmill three-fold further than low-capacity runners (LCR) (Koch & Britton, Physiol. Genomics 5:45, 2001). Two groups of nine female rats fed Purina Chow were shipped by air from Toledo to Grand Forks. After acclimatization for 3 weeks, HCR rats weighed 11 % less (p<0.025) than LCR rats with less fat free mass, mean ± SE, (179g ± 6.8 vs. 210 ± 9.5, p<0.02) according to bioelectrical impedance analysis. Then rats were anesthetized and organs were removed for analysis. Heart weight÷body weight was 7.5% greater in HCR (p<0.05). Metallic elements were measured by atomic absorption spectrometry after destruction of organic matter. Copper in gastrocnemius and soleus (µg/dry g) was 3.82 ± 0.10 vs. 3.15 ± 0.06 (p<0.0001) and 4.65 ± 0.43 vs.2.83 ± 0.23 (p<0.003) in HCR and LCR, respectively. Similar data on iron were 83 ± 2.8 vs. 70 ± 2.3 (p<0.003) and 173 ± 10.2 vs.139 ± 6.3 (p<0.015). Zinc in these muscles was unaffected (p>0.5). Angiotensin converting enzyme, the fitness enzyme (Montgomery, et al., Nature 393:221,1998), was unaltered in aorta, cardiac ventricle, and skeletal muscles (p>0.15). Increased respiratory proteins dependent on Cu or Fe may contribute to the running ability of HCR rats.