TY - JOUR
T1 - Passive length-force properties of senescent diaphragm
T2 - Relationship with collagen characteristics
AU - Gosselin, L. E.
AU - Martinez, D. A.
AU - Vailas, A. C.
AU - Sieck, G. C.
PY - 1994
Y1 - 1994
N2 - The purpose of this study was to examine the effect of aging on collagen concentration and extent of nonreducible collagen cross-linking as well as with the passive length-force relationship of the diaphragm muscle. Midcostal diaphragm muscle strips from young (6 mo) and senescent (24 mo) Fischer 344 rats were perfused in a tissue bath containing mammalian Ringers solution (25°C) aerated with 95% O2-5% CO2. The segments were lengthened and shortened from 85 to 115% of optimal length (L(o)) at a constant velocity (0.6 L(o)/s), and the passive force was measured. Hydroxyproline (HYP) and the mature nonreducible collagen cross-link, hydroxylysylpyridinoline (HP), were measured by high-pressure liquid chromatography. The resting force at L(o) did not differ between young and senescent diaphragm muscles. However, the senescent diaphragm exhibited greater passive force compared with the young (P < 0.05) at lengths >110% of L(o). High-pressure liquid chromatography analysis revealed a higher concentration of HYP in the senescent compared with the young diaphragm (9.32 ± 0.83 and 6.59 ± 0.78 g HYP/mg dry wt, respectively; P < 0.05). Additionally, the content of HP was greater in the senescent compared with the young diaphragm (1.16 ± 0.05 and 0.91 ± 0.05 mol HP/mol collagen, respectively; P < 0.05). These results suggest that diaphragm collagen metabolism, maturation, and the passive length-force characteristics of the muscle are altered with senescence.
AB - The purpose of this study was to examine the effect of aging on collagen concentration and extent of nonreducible collagen cross-linking as well as with the passive length-force relationship of the diaphragm muscle. Midcostal diaphragm muscle strips from young (6 mo) and senescent (24 mo) Fischer 344 rats were perfused in a tissue bath containing mammalian Ringers solution (25°C) aerated with 95% O2-5% CO2. The segments were lengthened and shortened from 85 to 115% of optimal length (L(o)) at a constant velocity (0.6 L(o)/s), and the passive force was measured. Hydroxyproline (HYP) and the mature nonreducible collagen cross-link, hydroxylysylpyridinoline (HP), were measured by high-pressure liquid chromatography. The resting force at L(o) did not differ between young and senescent diaphragm muscles. However, the senescent diaphragm exhibited greater passive force compared with the young (P < 0.05) at lengths >110% of L(o). High-pressure liquid chromatography analysis revealed a higher concentration of HYP in the senescent compared with the young diaphragm (9.32 ± 0.83 and 6.59 ± 0.78 g HYP/mg dry wt, respectively; P < 0.05). Additionally, the content of HP was greater in the senescent compared with the young diaphragm (1.16 ± 0.05 and 0.91 ± 0.05 mol HP/mol collagen, respectively; P < 0.05). These results suggest that diaphragm collagen metabolism, maturation, and the passive length-force characteristics of the muscle are altered with senescence.
KW - connective tissue
KW - extracellular matrix
KW - skeletal muscle
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U2 - 10.1152/jappl.1994.76.6.2680
DO - 10.1152/jappl.1994.76.6.2680
M3 - Article
C2 - 7928900
AN - SCOPUS:0028282605
SN - 8750-7587
VL - 76
SP - 2680
EP - 2685
JO - Journal of applied physiology
JF - Journal of applied physiology
IS - 6
ER -