The Effects of Aging on the Intramuscular Connective Tissue.
Int J Mol Sci
; 23(19)2022 Sep 21.
Article
in En
| MEDLINE
| ID: mdl-36232366
ABSTRACT
The intramuscular connective tissue plays a critical role in maintaining the structural integrity of the muscle and in providing mechanical support. The current study investigates age-related changes that may contribute to passive stiffness and functional impairment of skeletal muscles. Variations in the extracellular matrix in human quadriceps femoris muscles in 10 young men, 12 elderly males and 16 elderly females, and in the hindlimb muscles of 6 week old, 8 month old and 2 year old C57BL/6J male mice, were evaluated. Picrosirius red, Alcian blue and Weigert Van Gieson stainings were performed to evaluate collagen, glycosamynoglycans and elastic fibers. Immunohistochemistry analyses were carried out to assess collagen I, collagen III and hyaluronan. The percentage area of collagen was significantly higher with aging (p < 0.01 in humans, p < 0.001 in mice), mainly due to an increase in collagen I, with no differences in collagen III (p > 0.05). The percentage area of elastic fibers in the perimysium was significantly lower (p < 0.01) in elderly men, together with a significant decrease in hyaluronan content both in humans and in mice. No significant differences were detected according to gender. The accumulation of collagen I and the lower levels of hyaluronan and elastic fibers with aging could cause a stiffening of the muscles and a reduction of their adaptability.
Key words
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Connective Tissue
/
Hyaluronic Acid
Limits:
Aged
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Animals
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Female
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Humans
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Male
Language:
En
Journal:
Int J Mol Sci
Year:
2022
Document type:
Article
Affiliation country:
Italy