Prostaglandin H synthase-2 in human gestational tissues: Regulation in amnion

Using reverse transcriptase-polymerase chain reaction we have established that mRNAs for prostaglandin H synthases 1 and 2 (PGHS-1 and PGHS-2) are present in amnion, chorion and decidua from women both at term before and after the onset of labour and from women at 28-35 weeks of gestation before the onset of labour. By Western blot analyses we have demonstrated that epidermal growth factor, interleukin 1β and phorbol 12-myristate 13-acetate all increase PGHS-2 amounts in amnion cells. The degree of stimulation caused by these substances (218-311 per cent) is less than the increase in prostaglandin production usually generated (five- to 10-fold). Hence we believe that these substances may have multiple sites of action in the pathways of arachidonic acid metabolism.