Collagen and glycosaminoglycan synthesis of injured gastrocnemius muscle in rat.
The synthesis of collagen and glycosaminoglycans in a partially ruptured gastrocnemius muscle were studied in 30 rats by giving a single 3H-labelled proline and 14C-labelled glucosamine injection intraperitoneally 2-21 days after a standard transverse contusion injury induced to the left calf of the animals. Both injured and contralateral uninjured gastrocnemius muscles were cut into four analogous 5-mm thick transverse pieces using the center of injury as a site for the middle incision in the injured muscle. The muscle slices were homogenized, dialyzed and then burned in a sample oxidizer which automatically divides the two radioisotopes into two different sample flasks. The radioactivities were measured using a liquid scintillation spectrometer. The content of glycosaminoglycans within the site of injury increased to a maximum 5 days after trauma, and decreased in amount thereafter. The uptake of 3H-proline indicating the synthesis of collagen was very low 5 days after trauma but increased to a maximum between the 10th and 14th day; more intensively in the proximal border of the injury than in the distal one. The uptake decreased again in amount 21 days after trauma. Burning of an in vivo radioactively labelled sample in a sample oxidizer provides a simple method in determination of the two radioactive isotopes as indicators of two main components of granulation and scar tissue.
D000818:Animals; D002250:Carbon Radioisotopes; D003094:Collagen / Q000096:biosynthesis*; D005944:Glucosamine / Q000378:metabolism; D006025:Glycosaminoglycans / Q000096:biosynthesis*; D008297:Male; D009132:Muscles / Q000293:injuries* / Q000378:metabolism; D011392:Proline / Q000378:metabolism; D051381:Rats; D011919:Rats, Inbred Strains; D013997:Time Factors; D014316:Tritium; D014945:Wound Healing
D002250:Carbon Radioisotopes; D006025:Glycosaminoglycans; D014316:Tritium; D003094:Collagen; D011392:Proline; D005944:Glucosamine