Effect of estradiol and relaxin on collagen and non-collagen protein synthesis by mammary fibroblasts.

In order to determine the effect of relaxin and estradiol on collagen and noncollagen synthesis by mammary gland fibroblasts, fibroblasts isolated from guinea pig mammary glands were grown on plastic or Cytodex-3 collagen coated microcarriers. On plastic, estradiol (600 pg/ml) increased the incorporation of tritiated glycine into collagen. Non-collagenous protein synthesis was increased at all concentrations of estradiol, but it was greatest with 200 pg/ml estradiol. On Cytodex-3, 400 pg/ml estradiol increased the synthesis of collagen and non-collagenous protein. Relaxin (1 microgram/ml) did not affect collagen synthesis but decreased the synthesis of non-collagenous protein.