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Type I collagen synthesis and degradation in peritendinous tissue after exercise determined by microdialysis in humans
Author(s) -
Langberg Henning,
Skovgaard Dorthe,
Petersen Lars J.,
Bülow Jens,
Kjær Michael
Publication year - 1999
Publication title -
the journal of physiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.802
H-Index - 240
eISSN - 1469-7793
pISSN - 0022-3751
DOI - 10.1111/j.1469-7793.1999.00299.x
Subject(s) - microdialysis , chemistry , in vivo , interstitial fluid , tendon , achilles tendon , basal (medicine) , type i collagen , interstitial space , endocrinology , medicine , andrology , extracellular , anatomy , biochemistry , biology , microbiology and biotechnology , insulin
1 Physical activity is known to increase type I collagen synthesis measured as the concentration of biomarkers in plasma. By the use of microdialysis catheters with a very high molecular mass cut‐off value (3000 kDa) we aimed to determine local type I collagen synthesis and degradation in the peritendinous region by measuring interstitial concentrations of a collagen propeptide (PICP; 100 kDa) and a collagen degradation product (ICTP; 9 kDa) as well as an inflammatory mediator (PGE 2 ). 2 Seven trained human runners were studied before and after (2 and 72 h) 3 h of running (36 km). Two microdialysis catheters were placed in the peritendinous space ventral to the Achilles’ tendon under ultrasound guidance and perfused with a Ringer‐acetate solution containing 3 H‐labelled human type IV collagen and [15‐ 3 H(N)]PGE 2 for in vivo recovery determination. Relative recovery was 37–59% (range of the s.e.m. values) for both radioactively labelled substances. 3 PICP concentration decreased in both interstitial peritendinous tissue and arterial blood immediately after exercise, but rose 3‐fold from basal 72 h after exercise in the peritendinous tissue (55 ± 10 μg l −1 , mean ± s.e.m. (rest) to 165 ± 40 μg l −1 (72 h), P < 0·05 ) and by 25% in circulating blood (160 ± 10 μg l −1 (rest) to 200 ± 12 μg l −1 (72 h), P < 0·05 ). ICTP concentration did not change in blood, but decreased transiently in tendon‐related tissue during early recovery after exercise only. PGE 2 concentration increased in blood during running, and returned to baseline in the recovery period, whereas interstitial PGE 2 concentration was elevated in the early recovery phase. 4 The findings of the present study indicate that acute exercise induces increased formation of type I collagen in peritendinous tissue as determined with microdialysis and using dialysate fibre with a very high molecular mass cut‐off. This suggests an adaptation to acute physical loading also in non‐bone‐related collagen in humans.