DOS Kongressen 2014 ·
213
A month of heavy resistance exercise increases the
amount of Collagen XIV in the endomysium close to
the human MTJ
Jens Rithamer Jakobsen, Abigail Mackey, Andreas Knudsen, Manuel Koch,
Michael Kjaer, Michael Rindom Krogsgaard
Department of sportstraumatology M51, , Bispebjerg University Hospital;
Institute of Sports Medicine Copenhagen, Department of Orthopaedic Surgery
M, and Department of Biom, Bispebjerg University Hospital and University of
Copenhagen; Institute for Dental Research and Oral Musculoskeletal Biology,
and Center for Biochemistry, Medical Faculty, University of Cologne, Cologne,
Germany
Background:
Strain injuries are a common cause of absence from sports. They
occur most often at the myotendinous junction (MTJ). So far the best preven-
tion seems to be heavy resistance exercise (HRE), but it is unknown which adap-
tions HRE induces in the human MTJ that could explain this lowering in risk of
strain injuries.
Purpose / Aim of Study:
To investigate how the MTJ and endomysium adapts
to one month of HRE training.
Materials and Methods:
Ten patients scheduled for cruciate ligament recon-
struction with a hamstrings graft were randomized into either a control group
or a training group (1 month of HRE). At the operation, samples were collected
from the semitendinosus and gracilis MTJ and fixed in liquid nitrogen-cooled
isopentane. Samples were sectioned and stained with immunofluorescent anti-
bodies against seven collagen types. The amounts of collagen were estimated
visually using a scale from 0-2 where 2 is the highest amount.
Findings / Results:
Compared with our control group, a significantly higher
collagen XIV content of the muscle endomysium (P = 0,0132) was found in the
training group. No significant differences for any of the investigated collagen
types where seen at the MTJ.
Conclusions:
1 month of HRE does not lead to detectable increases in the
amount of collagen I, III, IV, VI, XII and XIV at the MTJ. However, it leads to a
significant increase in collagen XIV content in the endomysium of human muscle
tissue close to the MTJ. These findings suggest that collagen XIV has a role in the
adaptation of the connective tissue sheath to heavy loading. It is possible that
longer training periods are required to induce measurable increases for the other
collagen types at the MTJ or alternatively that structural changes increasing the
muscle-tendon contact area explain the improved resistance to strain injury at
the MTJ after HRE.
160.
