Abstract
The effects of 13 kinds of prostaglandins (PGs) on the activities of a human gingival fibroblast (ATCC CRL 1292) were widely examined . PGA1 and PGD2 caused deformation in morphology of the fibroblast, and all PGs tested showed inhibitory effects on proliferation, DNA synthesis, collagen synthesis, and noncollagenous protein synthesis in the fibroblast under the conditions used in this study, and many PGs tested increased the intracellular cyclic AMP (cAMP) level. Therefore, the mechanism by which PGE2 inhibits DNA synthesis was examined in view of the increased cAMP level . The inhibitory effect of PGE2 on DNA synthesis was not enhanced when the increase of intracellular cAMP level by PGE2 was accelerated by a cAMP-phosphodiesterase inhibitor (IBMX). Further the inhibitory effect of PGE2 on DNA synthesis was not weakened by inhibiting cAMP-dependent protein kinase (A-kinase).
It is suggested from the results that the inhibitory effect of PGE2 on DNA synthesis in the fibroblast is not mediated through the cAMP.A-kinase system but probably through other cellular signalling systems.
