RESPONSE OF HUMAN GINGIVAL FIBROBLASTS TO PROSTAGLANDINS

The effects of various prostaglandins (PGs) on the functions of human gingival fibroblasts (Gin-1 cells; ATCC CRL 1292) were examined by phase-contrast microscopy, cell-counting and radioautographic experiments. Tested PGs were PGA(1), PGA(2), PGB(1), PGB(2), PGD(2), PGE(1), PGE(2), PGF(1) alpha, PGF(2) alpha, PGI(2), 6-keto-PGF(1) alpha, 9 alpha-11 alpha-methanoepoxy-PGF(2) alpha, and thromboxane (TX) B-2. PGA(1) and PGD(2) at 30 mu M caused morphological deformation of Gin-1 cells. All the PGs tested at 30 mu M suppressed the proliferation of Gin-1 cells in the logarithmic growth phase. Furthermore, all the PGs tested at 10 mu M suppressed DNA synthesis, collagen synthesis, and noncollagenous protein synthesis in confluent Gin-1 cells, while exerting no effect on GAG synthesis. The concentrations of PGs used are beyond those found in healthy gingiva. However, in periodontitis the local concentrations of some PGs within the gingiva are expected to be extremely elevated beyond the physiological level. These results suggest that PGs may play an important role as a negative regulator in metabolism and some pathologic gingival conditions by suppressing the functions of gingival fibroblasts.