ROLE OF INTERFERON-ALPHA IN ARACHIDONIC-ACID METABOLISM BY THE RAT UTERI FROM SPAYED ANIMALS - EFFECT OF 17-BETA-ESTRADIOL

Interferon-like trophoblastic proteins modulate prostaglandin (PG) syn thesis from endometrium in early ovine and bovine pregnancy, We attemp ted to explore the effect of interferon (IFN)-alpha in the isolated ra t uterus from ovariectomized animals on the metabolism of labelled ara chidonic acid (AA), The experiments were performed with uterine prepar ations isolated from spayed rats treated or untreated with 17 beta-est radiol prior to sacrifice, The pre-incubation of uterine tissue isolat ed from ovariectomized rats with three different doses (4, 150 and 300 IU/ml) of IFN-alpha decreased the radioconversion of [C-14]AA into 6- keto PGF(1 alpha), PGF(2 alpha) and PGE(2), whereas the formation of t hromboxane B-2 (TXB(2)) decreased after treatment with 4 IU/ml of INF- alpha but was augmented with 150 and 300 IU/ml, The three doses used d iminished the synthesis of 5-hydroxyeicosatetraenoic acid (5-HETE) and increased the production of 12-HETE. We also studied the synthesis of uterine products of cyclooxygenase and lipoxygenase in uterine tissue from ovariectomized rats injected with 17 beta-estradiol and preincub ated with IFN-alpha, We found that the three doses of IFN-alpha dimini shed the production of 6-keto-PGF(1 alpha), PGE(2), PGF(2 alpha) and T XB(2) as well as 5-HETE and 12-HETE, These findings show that IFN-alph a modifies the basal synthesis of PGs from uterine tissue, Ovine and b ovine trophoblastic protein prevents luteolysis by inhibiting the synt hesis of PGF(2 alpha). On the other hand, IFN-alpha shows 70% homology with ovine trophoblastic protein and binds to the same receptor, The results of the present study suggest that IFN-alpha may also act in th e rat as a luteotrophic agent.