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Use of cis-[18F]fluoro-proline for assessment of exercise-related collagen synthesis in musculoskeletal connective tissue.

Skovgaard D, Kjaer A, Heinemeier KM, Brandt-Larsen M, Madsen J, Kjaer M - PLoS ONE (2011)

Bottom Line: The PET-derived results were compared to mRNA expression of collagen type I and III.Tibial bone had the highest SUV that increased significantly (p<0.001) from the early (60 min) to the late (240 min) PET scan, while SUV in tendon and muscle decreased (p<0.001).The tissue-specific differences with the highest basal uptake in bone are in accordance with earlier studies relying on tissue incorporation of isotopic-labelled proline.

View Article: PubMed Central - PubMed

Affiliation: Institute of Sports Medicine Copenhagen, Bispebjerg Hospital and Faculty of Health Sciences, University of Copenhagen, Copenhagen, Denmark. dskovgaard@dadlnet.dk

ABSTRACT
Protein turnover in collagen rich tissue is influenced by exercise, but can only with difficulty be studied in vivo due to use of invasive procedure. The present study was done to investigate the possibility of applying the PET-tracer, cis-[(18)F]fluoro-proline (cis-Fpro), for non-invasive assessment of collagen synthesis in rat musculoskeletal tissues at rest and following short-term (3 days) treadmill running. Musculoskeletal collagen synthesis was studied in rats at rest and 24 h post-exercise. At each session, rats were PET scanned at two time points following injection of cis-FPro: (60 and 240 min p.i). SUV were calculated for Achilles tendon, calf muscle and tibial bone. The PET-derived results were compared to mRNA expression of collagen type I and III. Tibial bone had the highest SUV that increased significantly (p<0.001) from the early (60 min) to the late (240 min) PET scan, while SUV in tendon and muscle decreased (p<0.001). Exercise had no influence on SUV, which was contradicted by an increased gene expression of collagen type I and III in muscle and tendon. The clearly, visible uptake of cis-Fpro in the collagen-rich musculoskeletal tissues is promising for multi-tissue studies in vivo. The tissue-specific differences with the highest basal uptake in bone are in accordance with earlier studies relying on tissue incorporation of isotopic-labelled proline. A possible explanation of the failure to demonstrate enhanced collagen synthesis following exercise, despite augmented collagen type I and III transcription, is that SUV calculations are not sensitive enough to detect minor changes in collagen synthesis. Further studies including kinetic compartment modeling must be performed to establish whether cis-Fpro can be used for non-invasive in-vivo assessment of exercise-induced changes in musculoskeletal collagen synthesis.

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Related in: MedlinePlus

Gene expression of COL1A1 and COL3A1.COL1A1 and CoL3A1 mRNA normalized to tissue weight, presented as fold changes in the exercise group (filled bars) relative to the mean of the control group (open bars) in Achilles tendon and soleus muscle. In tendon COL3A1 mRNA was significantly increased (p<0.05) in the Exercise group and COL1A1 mRNA showed a strong tendency to an increase (p = 0.09). In exercised soleus muscle both COL1A1 (p<0.01) and COL3A1 (p<0.001) were significantly increased. Values are geometric means ± SEM.
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pone-0016678-g004: Gene expression of COL1A1 and COL3A1.COL1A1 and CoL3A1 mRNA normalized to tissue weight, presented as fold changes in the exercise group (filled bars) relative to the mean of the control group (open bars) in Achilles tendon and soleus muscle. In tendon COL3A1 mRNA was significantly increased (p<0.05) in the Exercise group and COL1A1 mRNA showed a strong tendency to an increase (p = 0.09). In exercised soleus muscle both COL1A1 (p<0.01) and COL3A1 (p<0.001) were significantly increased. Values are geometric means ± SEM.

Mentions: The general range of Ct values was 17–29. Compared to the control group, the soleus muscle of the exercise group exhibited a ∼2 fold increase of COL1A1 mRNA (p<0.01) and a ∼5 fold increase of COL3A1 mRNA (p<0.001). This was in Achilles tendon accompanied by a significant ∼2 fold increase of COL3A1 mRNA (p<0.05) and a strong tendency towards enhancement of COL1A mRNA (1.8 fold, p = 0.09) (figure 4).


Use of cis-[18F]fluoro-proline for assessment of exercise-related collagen synthesis in musculoskeletal connective tissue.

Skovgaard D, Kjaer A, Heinemeier KM, Brandt-Larsen M, Madsen J, Kjaer M - PLoS ONE (2011)

Gene expression of COL1A1 and COL3A1.COL1A1 and CoL3A1 mRNA normalized to tissue weight, presented as fold changes in the exercise group (filled bars) relative to the mean of the control group (open bars) in Achilles tendon and soleus muscle. In tendon COL3A1 mRNA was significantly increased (p<0.05) in the Exercise group and COL1A1 mRNA showed a strong tendency to an increase (p = 0.09). In exercised soleus muscle both COL1A1 (p<0.01) and COL3A1 (p<0.001) were significantly increased. Values are geometric means ± SEM.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3037959&req=5

pone-0016678-g004: Gene expression of COL1A1 and COL3A1.COL1A1 and CoL3A1 mRNA normalized to tissue weight, presented as fold changes in the exercise group (filled bars) relative to the mean of the control group (open bars) in Achilles tendon and soleus muscle. In tendon COL3A1 mRNA was significantly increased (p<0.05) in the Exercise group and COL1A1 mRNA showed a strong tendency to an increase (p = 0.09). In exercised soleus muscle both COL1A1 (p<0.01) and COL3A1 (p<0.001) were significantly increased. Values are geometric means ± SEM.
Mentions: The general range of Ct values was 17–29. Compared to the control group, the soleus muscle of the exercise group exhibited a ∼2 fold increase of COL1A1 mRNA (p<0.01) and a ∼5 fold increase of COL3A1 mRNA (p<0.001). This was in Achilles tendon accompanied by a significant ∼2 fold increase of COL3A1 mRNA (p<0.05) and a strong tendency towards enhancement of COL1A mRNA (1.8 fold, p = 0.09) (figure 4).

Bottom Line: The PET-derived results were compared to mRNA expression of collagen type I and III.Tibial bone had the highest SUV that increased significantly (p<0.001) from the early (60 min) to the late (240 min) PET scan, while SUV in tendon and muscle decreased (p<0.001).The tissue-specific differences with the highest basal uptake in bone are in accordance with earlier studies relying on tissue incorporation of isotopic-labelled proline.

View Article: PubMed Central - PubMed

Affiliation: Institute of Sports Medicine Copenhagen, Bispebjerg Hospital and Faculty of Health Sciences, University of Copenhagen, Copenhagen, Denmark. dskovgaard@dadlnet.dk

ABSTRACT
Protein turnover in collagen rich tissue is influenced by exercise, but can only with difficulty be studied in vivo due to use of invasive procedure. The present study was done to investigate the possibility of applying the PET-tracer, cis-[(18)F]fluoro-proline (cis-Fpro), for non-invasive assessment of collagen synthesis in rat musculoskeletal tissues at rest and following short-term (3 days) treadmill running. Musculoskeletal collagen synthesis was studied in rats at rest and 24 h post-exercise. At each session, rats were PET scanned at two time points following injection of cis-FPro: (60 and 240 min p.i). SUV were calculated for Achilles tendon, calf muscle and tibial bone. The PET-derived results were compared to mRNA expression of collagen type I and III. Tibial bone had the highest SUV that increased significantly (p<0.001) from the early (60 min) to the late (240 min) PET scan, while SUV in tendon and muscle decreased (p<0.001). Exercise had no influence on SUV, which was contradicted by an increased gene expression of collagen type I and III in muscle and tendon. The clearly, visible uptake of cis-Fpro in the collagen-rich musculoskeletal tissues is promising for multi-tissue studies in vivo. The tissue-specific differences with the highest basal uptake in bone are in accordance with earlier studies relying on tissue incorporation of isotopic-labelled proline. A possible explanation of the failure to demonstrate enhanced collagen synthesis following exercise, despite augmented collagen type I and III transcription, is that SUV calculations are not sensitive enough to detect minor changes in collagen synthesis. Further studies including kinetic compartment modeling must be performed to establish whether cis-Fpro can be used for non-invasive in-vivo assessment of exercise-induced changes in musculoskeletal collagen synthesis.

Show MeSH
Related in: MedlinePlus