Effects of interferons on proliferation and collagen synthesis of rat palatal wound fibroblasts.

The purpose was to select drugs that specifically reduce collagen synthesis by palatal granulation fibroblasts without affecting their proliferation. Granulation fibroblasts were obtained from 8-day-old palatal mucoperiosteal wounds and normal fibroblasts from palatal tissue of unwounded rats. Cultured cells were treated with interferon-alpha2b, interferon-beta and interferon-gamma (0, 100, 1000, and 10000 U/ml). Cell proliferation was measured by [3H]thymidine incorporation. Collagen synthesis and non-collagenous protein synthesis were determined from the incorporation of [3H]proline. None of the interferons significantly inhibited the proliferation of either type of fibroblasts. Interferon-alpha2b had no effect on the variables studied at the dosages used. Interferon-beta reduced collagen synthesis of granulation fibroblasts without affecting their non-collagenous protein synthesis or protein synthesis by normal fibroblasts. Interferon-gamma reduced collagen synthesis of both types of fibroblast and the non-collagenous protein synthesis of granulation fibroblasts. These data show that interferon-beta specifically reduces collagen synthesis by oral granulation fibroblasts without affecting normal palatal fibroblasts.