Ionizing radiation induces early, sustained increases in collagen biosynthesis: a 48-week study in mouse skin and skin fibroblast cultures.
Groups of 10 CF1 female mice, irradiated to the thorax with a dual-head 137Cs gamma-RAY source, received single doses of 0, 5, 10, 15, or 25 Gy. One to forty-eight weeks later collagen synthesis was measured in minced skin specimens incubated in medium containing [3H]proline and then assayed for radioactive hydroxyproline. A progressive, generally dose-dependent increase in collagen biosynthesis, up to 50% above control sites, was found 1, 4, and 12 weeks after radiation exposure. These changes showed further small fluctuations at 12-36 weeks, increasing again at the 48-week interval. At the same times throughout the study fibroblasts were cultured from skin explants. Following the second subculture, these cells were also incubated in medium containing [3H]proline, and collagen synthesis was again determined by [3H]hydroxyproline assay. At all radiation dose levels studied, collagen production increased threefold by 12 weeks postradiation and remained elevated for the 48-week duration of the study. In vitro radiation dose response differences were not observed.
Panizzon
R G
RG
Department of Dermatology, Rush-Presbyterian-St. Luke's Medical Center, Chicago, Illinois.
Hanson
W R
WR
Schwartz
D E
DE
Malkinson
F D
FD
D000818:Animals; D002588:Cesium Radioisotopes; D003094:Collagen / Q000096:biosynthesis*; D005260:Female; D005347:Fibroblasts / Q000378:metabolism / Q000473:pathology / Q000528:radiation effects*; D005355:Fibrosis; D005720:Gamma Rays; D051379:Mice; D012867:Skin / Q000378:metabolism / Q000473:pathology / Q000528:radiation effects*; D013997:Time Factors
D002588:Cesium Radioisotopes; D003094:Collagen