Deciduogenic effect of prostaglandins in the pseudopregnant rabbit

Intrauterine implants made of Silastic or wax and containing various additives, including prostaglandins (PGs), were used to characterize some of the factors involved in deciduogenesis in rabbits. Implants were inserted into uteri on Day 6 of pseudopregnancy and the response was assessed by light microscopy on Day 10. The surface area of decidual tissue in histological sections was employed as an index of the degree of decidualization obtained. PGE-2, PGF-2alpha and arachidonic acid each elicited a prominent decidual response, PGE-2 being most potent. Implants which released histamine or oestradiol-17beta had a very slight decidualizing effect in some females. Control implants and implants releasing dibutyryl cyclic-AMP had no deciduogenic influence. All implants, regardless of additive content, induced a symplasmic transformation of the uterine surface epithelium. It is concluded that PGs and the distension caused by the implant may be involved in deciduogenesis in the rabbit.