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Collagen synthesis activation after eccentric contraction-induced muscle damage in rats at different ages
PRODUCTIONOF
COLLAGEN SYNTHESIS ACTIVATION AFTER ECCENTRIC CONTRACTION- INDUCED MUSCLE DAMAGE IN RATS AT DIFFERENT AGES V. Kovanen**, A. M. Ahtikoski, S. 0. A. Koskinen, T. E. S. Takala and L. E. Gosselin* Departments of **Health Sciences and Biology of Physical Activity, University of Jyvtiskylii,Finland and *Department of Physical Therapy and Exercise Science, State University of New York,@ BufSalo, USA
PROSTCLA~DIY
PGE, 1~ THE
~ILsCLE
DURING DYU.AMIC \IUSCLECO~TRhCTIO\S H. Lanabe&.‘. M.Kazamouzis’. M. Kjaef. B. Salnn ‘Department of Clinical ‘Labolatory of Biologd
Physmlon\._. Blspcblerc _ Horclrz:. Detrnari; Chemistry. Unl. oafThsssaicn.h.. C:?:ce ‘Sports Med. Research Cnlt. BlspsbJerg Hospiral. Dsr.mar~
Purpose: The production
of PGEl in the muscles 113s measured subjects during 60 min of dynnmlc exercise. Methods: Four microdialysis catheters were inserted into the Vastus Lateralis muscle of the left leg and four into the right leg of two volunteers (men, 23 and 2-1 years). The microdialysis catheters were perfused Lvith a Ringer-acetate solution using a infusion rate of 3 ~1 mm. ‘After an equilibration period of 60 min samples were collected during a) a resting period of 60 min. b) an exercising period of 60 min. The exercising period consisted of dynamic exercise of the knee extensors at one leg at workload of20 XV. Results: The level of PGE? (meat&EM) in the dialysed fluid was: during rest 3IS * 52 pg:ml; during exercise 2939 I 612 pg/ml (p < 0.05). To obtain the interstitial concentration of PGE, in the extra cellular fluid of the muscle the internal reference method (4000 Bq ~1 ‘H-PGE?) was used to find the in-viva recovery of PGE,. The reco\el?; was ll “,o during rest and 75 % during exercise. The interstitial concentration of PGE, in the extra cellular fluid of the Vastus Lateralis muscle was then calculated to be: m healthy
The expression of fibrillar collagens and prolyl 4hydroxylase (P4H) increases coordinatively both at the mRNA and protein level after eccentric exercise-induced muscle damage in young adult rats. The present study investigated the effect of age (6-, 12-, and 26 mo) on collagen synthesis and its regulation in Fischer 344 rat tibialis anterior muscle 7 days after eccentric contractions. TA muscles were subjected to forced lengthening contractions by electrical stimulation of the common peroneal nerve. There was an age-associated decline in the mRNA levels of type I and III collagens, and alfa-subunit of P4H, as well as P4H enzyme activity in both control and injured TA muscles. The relative responses were, however, significantly higher in the 26-mo rats than in the 6-mo rats. The steady state mRNA levels of TGF-Bl, regulator of collagen synthesis, did not change with age and increased to same extent (p<.Ol-.05) in each age group after muscle damage. The results suggest that older rats have a high capacity to response to muscle damage and regeneration by activating collagen synthesis related gene expression.
Conclusion: Interstitial concentration of PGE, in the extra cellular fluid of the Vastus Lateralis muscle increases significantly (p
PRODUCTIONOF PGE,ANDTXB,AROUNDTHEACHILLES TENDONINHUMANSDURINGEXERCISE
H. Lanaberg’.‘, M.Kazamouzis’, D. Skovgaard’, J.Biilow’, B. Saltin’, M. Kjsr’ ‘Departmentof Clinical Physiology, Bispebjerg Hospital, Denmark ‘Labolatory of Biological Chemistry, Uni. of Thessaloniki, Greece ‘Sports Med. Research Unit, Bispebjerg Hospital, Denmark
‘Ike new method of estimation ofhuman skeletal muscle’s tension allowed to measure Young.‘s modulus of soft tissues which was defined according to the slope of histerpsis curve of the experimental subject rellecting its deformation dependence of the imposed force. This method was developed in our Institute (1984). It permited to study the variations oftnuscle tension of sportsman duritip isometric loads. The work has been carried out on the Biceps Brahii of young men: 18-25 years (23 persons). The researches showed that Young’s modulus of rest muscles was 36 kPa47 kPa_ The muscle loading 1 kg has indexes 45kPa-65 kPa The load of4 k.8 causes the increase of the muscles tissues tension in 2-2,s times. It is necessary to note that if the load increases 5 kg? index of tension will be invariable but the tremor will take place. Young’s modulus value dependens on level of physical development of persons the sportsmen’s Biceps Brahii has sublinear character of dependence “ Young’s modulus - Force“, the persons with midlle level of physical development has liner character of dependence “Young’s tnodulns - Force” and the weak people (often ill) have super liner one. The investigatiotres of skeletal muscles o f young men in high temperature (sayna) showed that contrary to increase the blood flow the tension of skeletal muscles is decreased by l>-25%.
Purpose: The production of
PGEz aad TX& around the Achilles tendon was measured in humans during 30 mm of inter&tent static exercise. Methods: Two microdialysis catheters (CMA 60; CR/w Microdialysis AB) were inserted just ventral to the Achilles tendon in each leg in seven healthy subjects (mean age 26+1 (years ? SEM)). The microdialysis catheters were perfused with a Ringer-acetate solution containing Dextran-70 and ‘H-prostaglandin (4000 Bq/l.d) at a infusion rate of 1 @min. After an equilibration period of 60 min samples were collected during a) a resting period of 90 mm, b) aa exercising period of 30 mm, c) a resting period of 60 mm. The exercising period consisted of intermittent (1.5 set contraction/l.5 relaxation) static contraction of the m. triceps surae with a torque moment of 1 x Body weight.
Results: Calculated interstitial concentrations (mean t SEM):
~1 Conclusion: During intermittent static exercise the interstitial concentration of both PGE, and TX& was found to increase compared to rest, TXB, significantly @<0,05). Taken into account that the blood flow increases 3-4 fold during exercise the production of PCE: and TXB, is even higher.
126
COLLAGEN SYNTHESIS ACTIVATION AFTER ECCENTRIC CONTRACTION- INDUCED MUSCLE DAMAGE IN RATS AT DIFFERENT AGES V. Kovanen**, A. M. Ahtikoski, S. 0. A. Koskinen, T. E. S. Takala and L. E. Gosselin* Departments of **Health Sciences and Biology of Physical Activity, University of Jyvtiskylii,Finland and *Department of Physical Therapy and Exercise Science, State University of New York,@ BufSalo, USA
PROSTCLA~DIY
PGE, 1~ THE
~ILsCLE
DURING DYU.AMIC \IUSCLECO~TRhCTIO\S H. Lanabe&.‘. M.Kazamouzis’. M. Kjaef. B. Salnn ‘Department of Clinical ‘Labolatory of Biologd
Physmlon\._. Blspcblerc _ Horclrz:. Detrnari; Chemistry. Unl. oafThsssaicn.h.. C:?:ce ‘Sports Med. Research Cnlt. BlspsbJerg Hospiral. Dsr.mar~
Purpose: The production
of PGEl in the muscles 113s measured subjects during 60 min of dynnmlc exercise. Methods: Four microdialysis catheters were inserted into the Vastus Lateralis muscle of the left leg and four into the right leg of two volunteers (men, 23 and 2-1 years). The microdialysis catheters were perfused Lvith a Ringer-acetate solution using a infusion rate of 3 ~1 mm. ‘After an equilibration period of 60 min samples were collected during a) a resting period of 60 min. b) an exercising period of 60 min. The exercising period consisted of dynamic exercise of the knee extensors at one leg at workload of20 XV. Results: The level of PGE? (meat&EM) in the dialysed fluid was: during rest 3IS * 52 pg:ml; during exercise 2939 I 612 pg/ml (p < 0.05). To obtain the interstitial concentration of PGE, in the extra cellular fluid of the muscle the internal reference method (4000 Bq ~1 ‘H-PGE?) was used to find the in-viva recovery of PGE,. The reco\el?; was ll “,o during rest and 75 % during exercise. The interstitial concentration of PGE, in the extra cellular fluid of the Vastus Lateralis muscle was then calculated to be: m healthy
The expression of fibrillar collagens and prolyl 4hydroxylase (P4H) increases coordinatively both at the mRNA and protein level after eccentric exercise-induced muscle damage in young adult rats. The present study investigated the effect of age (6-, 12-, and 26 mo) on collagen synthesis and its regulation in Fischer 344 rat tibialis anterior muscle 7 days after eccentric contractions. TA muscles were subjected to forced lengthening contractions by electrical stimulation of the common peroneal nerve. There was an age-associated decline in the mRNA levels of type I and III collagens, and alfa-subunit of P4H, as well as P4H enzyme activity in both control and injured TA muscles. The relative responses were, however, significantly higher in the 26-mo rats than in the 6-mo rats. The steady state mRNA levels of TGF-Bl, regulator of collagen synthesis, did not change with age and increased to same extent (p<.Ol-.05) in each age group after muscle damage. The results suggest that older rats have a high capacity to response to muscle damage and regeneration by activating collagen synthesis related gene expression.
Conclusion: Interstitial concentration of PGE, in the extra cellular fluid of the Vastus Lateralis muscle increases significantly (p
PRODUCTIONOF PGE,ANDTXB,AROUNDTHEACHILLES TENDONINHUMANSDURINGEXERCISE
H. Lanaberg’.‘, M.Kazamouzis’, D. Skovgaard’, J.Biilow’, B. Saltin’, M. Kjsr’ ‘Departmentof Clinical Physiology, Bispebjerg Hospital, Denmark ‘Labolatory of Biological Chemistry, Uni. of Thessaloniki, Greece ‘Sports Med. Research Unit, Bispebjerg Hospital, Denmark
‘Ike new method of estimation ofhuman skeletal muscle’s tension allowed to measure Young.‘s modulus of soft tissues which was defined according to the slope of histerpsis curve of the experimental subject rellecting its deformation dependence of the imposed force. This method was developed in our Institute (1984). It permited to study the variations oftnuscle tension of sportsman duritip isometric loads. The work has been carried out on the Biceps Brahii of young men: 18-25 years (23 persons). The researches showed that Young’s modulus of rest muscles was 36 kPa47 kPa_ The muscle loading 1 kg has indexes 45kPa-65 kPa The load of4 k.8 causes the increase of the muscles tissues tension in 2-2,s times. It is necessary to note that if the load increases 5 kg? index of tension will be invariable but the tremor will take place. Young’s modulus value dependens on level of physical development of persons the sportsmen’s Biceps Brahii has sublinear character of dependence “ Young’s modulus - Force“, the persons with midlle level of physical development has liner character of dependence “Young’s tnodulns - Force” and the weak people (often ill) have super liner one. The investigatiotres of skeletal muscles o f young men in high temperature (sayna) showed that contrary to increase the blood flow the tension of skeletal muscles is decreased by l>-25%.
Purpose: The production of
PGEz aad TX& around the Achilles tendon was measured in humans during 30 mm of inter&tent static exercise. Methods: Two microdialysis catheters (CMA 60; CR/w Microdialysis AB) were inserted just ventral to the Achilles tendon in each leg in seven healthy subjects (mean age 26+1 (years ? SEM)). The microdialysis catheters were perfused with a Ringer-acetate solution containing Dextran-70 and ‘H-prostaglandin (4000 Bq/l.d) at a infusion rate of 1 @min. After an equilibration period of 60 min samples were collected during a) a resting period of 90 mm, b) aa exercising period of 30 mm, c) a resting period of 60 mm. The exercising period consisted of intermittent (1.5 set contraction/l.5 relaxation) static contraction of the m. triceps surae with a torque moment of 1 x Body weight.
Results: Calculated interstitial concentrations (mean t SEM):
~1 Conclusion: During intermittent static exercise the interstitial concentration of both PGE, and TX& was found to increase compared to rest, TXB, significantly @<0,05). Taken into account that the blood flow increases 3-4 fold during exercise the production of PCE: and TXB, is even higher.
126