A prostaglandin analogue which potently relaxes human uterus but not gut muscle

Abstract A prostaglandin analogue, (±)-5-(6-carboxyhexyl)-1-(3-cyclohexyl-3-hydroxypropyl) hydantoin was tested on strips of human isolated myometrium and gastro-intestinal muscle. The analogue usually caused marked dose-dependent myometrial relaxation and inhibition of spontaneous activity, with a threshold concentration sometimes of 10 pg/ml and a maximum effect at 10 ng/ml. In contrast 1–10 000 ng/ml had no effect on longitudinal muscle strips of human stomach or colon.