Expression of glucosamine trisaccharides on the rat uterine surface is altered by clomiphene citrate. II. Combination with ovarian hormones

Summary d a single administration of clomiphene citrate (CC), a synthetic oestrogen that is prescribed for infertility treatment, in combination with either a single administration of oestradiol 17 (E2) or progesterone (P4) to assess the combined effects of these hormones on the uterine surface. The aim of these experiments was to investigate how CC in combination with these hormones affected both expression of oligosaccharides on the uterine surface and membrane architecture further elucidating CCs agonistic/antagonistic properties. Ovariectomized sexually mature rats were given combinations of E2 and CC (E2+CC) or P4 and CC (P4+CC) or P4 and E2 (P4+E2) and were killed 24h later. Uterine tissue was labelled with the lectin Phytolacca americana conjugated with avidin and subsequently labelled with biotinylated ferritin and prepared for transmission electron microscopy. Results of the administration of these hormone combinations indicate that CC, when administered in conjunction with E2, had the ability to downregulate expression of oligosaccharides on the membrane surface caused by E2. When administered with P4, CC had the ability to upregulate the effects of P4. Thus, when combined with E2, CC has an antagonistic effect but when combined with P4, CC has an agonistic effect.