Catechol oestrogens stimulate and direct prostaglandin synthesis.

We have tested the action of a catechol oestrogen -2,3,17 beta-trihydroxy oestra-1,3,5 (10)-triene (2-OH oestradiol) in stimulating prostaglandin (PG) production by an homogenate of rat uterus. Marked and dose dependent stimulation was observed in PGF2 alpha and PGE2 production using 20-250 microM concentrations of catechol oestrogen; a concentration of 250 microM 2-OH oestradiol resulted in a 23 fold increase in PGF2 alpha production with a 50% reduction in the synthesis of 6-keto PGF1 alpha. Tryptophan, catechol and glutathione were without effect on PGF2 alpha and PGE2 production whereas adrenalin stimulated the production of all PGs, although the increase was less than that seen with 2-OH oestradiol. Oestradiol had a slight stimulatory action on PGF2 alpha production which reached a maximum at around 40 microM but had a more marked stimulation of 6-keto PGF1 alpha formation. Stimulation of prostaglandin production by oestradiol and 2-OH oestradiol showed no variation at different stages of the rat oestrous cycle. The use of 5 to 100 mg of tissue/ml gave similar product distribution although the effect of catechol oestrogen both in terms of stimulation of E and F formation (expressed per mg of tissue) and in its action on product distribution was more marked at lower concentrations of tissue.