Fetal lambs at term. Effect of ONO-11113 on prostaglandin release from the ductus venosus sphincter. (a) 6-keto-PGF1α, (b) PGE2 (n=4–5 for both compounds). Contractile responses to ONO-11113 are 387±46, 647±75, and 821±133 mg, respectively with 1, 7, and 100 nM.