تنظیم ترشح پروستاگلاندین E2 توسط مهارگران آنزیم های سیکلواکسیژناز ( نوعI و II) و پروستاگلاندین دهیدروژناز در سلولهای تروفوبلاست جفت انسانی

Recent studies in amnion and chorion trophoblasts have shown that&nbsp;glucocorticoids (GC) increase and decrease expression and activity of PGHS&nbsp;and PGDH enzymes respectively. However, the effects of GC on the expression&nbsp;of these enzymes in placental cells (PC) is unknown. &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; Human placenta were obtained from uncomplicated term pregnancies&nbsp;after elective cesarian section delivery. The dispresed cells were filtered and&nbsp;loaded on to a continous percoll gradient (5-70%) and after 72 hrs incubation&nbsp;of primary culture cell medium were washed and changed and then treated&nbsp;for 24 hrs in the presence or absence of arachidonic acid (5mM), plus various &nbsp;&nbsp; combinations of meloxicam (MEL , 1mM), indomethacin (Ind , 1mM)&nbsp;dexamethasone (DEX , 1mM) and sulphasalazine (SFZ , 1mM). fter incubation&nbsp;period cell mediums were collected for determination of PGE2&nbsp;by&nbsp;radioimmunoassay. One-way ANOVA test and student&rsquo;s t-test were used to&nbsp;assess statistical differences and ststistical significances were set at P<0.05. &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; Dexamethasone produced a significant , almost doubling of PGE2 output ,&nbsp;but this was not altered further by Mel. In the presece of SFZ alone , there was a&nbsp;significant approximate doubling increase in the output of PGE2&nbsp;(P<0.05) and&nbsp;this increase further in the presence of dexamethasone that increase was&nbsp;reduced by further addition of Mel (P<0.05) . Indomethacine treatment&nbsp;significantly reduced stimulation of PGE2 output seen in the presence of SFZ , or &nbsp;&nbsp; the further increase seen in cells treated with SFZ plus dexamethasone. &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; We conclude that basal PGE2&nbsp;output by term human PC likely depends on&nbsp;the activity of PGHS-1 not PGHS-2 .The effects of SFZ show the importance of&nbsp;endogenous PGDH in regulating PGE2 output , and interactions with SFZ , DEX&nbsp;and MEL suggest that GC stimulated output of&nbsp;PGE2&nbsp;by PC may be&nbsp;attributable to both up regulation of PGHS and decrease activity of PGDH.