Histopathological Changes of Subcutaneous Exposure to Glass Fibers in Rats

흰쥐에서 유리섬유의 피하삽입에 의한 경시적 병리조직학적 변화

To exanime in vivo tissue reactions of glass fibers, we injected glass fibers to rats subcutaneously. We made fibers of average dimensions of approximately $2{\mu}m$ in diameter and $60{\mu}m$ in length. After instilation of glass fiber we sacrificed rats sequentially at 1, 3 and 6 months. At 1 month after injection of glass fibers, the exposure area turned to yellow color and formed well-demarcated round mass. The average size of the mass was $1\times0.3cm$. Grossly detectable mass was decreased in size at 6 months compared to 1 or 3 months. Microscopically, strong foreign body reaction to glass fibers, inflammation and fibrosis were observed until 6 months. Foreign body reaction was increased up to 3 months, but it was decreased after 6 months. In scanning electron microscope, there was many bundles of glass fibers around the inflammation area, but the size of glass fibers were gradually reduced from 1 month to 6 months. These results suggest that subcutaneous exposure of glass fiber can provoke strong tissue reaction including foreign body granulomas, inflammation and fibrosis. But glass fiber itself did not produce any neoplastic changes.