The effect of CuIUD on estradiol receptor in the endometrium of rat — An autoradiographic study

Abstract

Autoradiography (ARG) and scanning microspectrophotometry were applied to study the changes of eosinophilic type II estradiol-binding sites in the endometrium of Sprague-Dawley rats with regular 4 -day estrous cycle, after 30 days of bearing a copper intrauterine device (CuIUD; 40.8mm²) in uterus.³H™estradiol™l7β (³H™E₂) labelled eosinophils were mainly distributed in the deep endometrial stroma and varied in quantity with the estrous cycle. In comparison with the contralateral uterine horn, the number of³H-E₂ labelled cells was significantly reduced in the CuIUD-bearing horn at estrus and diestrus The mean density of silver grains in the ARG positive eosinophils in the endometria exposed to CuIUD was decreased at diestrus, as compared with that in contralateral horns, and at proesttus with that in contralateral and control-group horns. The results suggested that the decrease of type II estradiol-binding sites induced by CuIUD may be closely related to the contraceptive action of copper.

Keywords

copper intrauterine device / estradiol receptor / eosinophil / autoradiography / uterine endometrium / rat

References

[1] TamayaT, et al.. The mechanism of action of the copper intrauterine device. Fertil Steril, 1976, 27: 767-72

[2] SugiuraY, MizuhiraV. Strong affinity of estradiol and its ligands for eosinophilic leucocytes in the rat and mouse uteri during the estrous cycle. Acta Histochem Cytochem, 1984, 17: 665-80

[3] 1983; 3 (1): 49–51.

[4] BrökelmannJ, FawcettDW. The localization of endogenous peroxidase in the rat uterus and its induction by estradiol. Biol Reprod, 1969, 1: 59-71

[5] LyttleCR, et al.. Eosinophils as the source of uterine nuclear type I estrogen binding sites. J Biol Chem, 1984, 259: 2697-700

[6] TchernitchinAN. Eosinophil-mediated non-genomic parameters of estrogen stimulation-A separate group of responses mediated by an independent mechanism. J Steroid Biochem, 1983, 19: 95-100

[7] TchernitchinAN, GalandP. Oestrogen levels in the blood, not in the uterus, determine uterine eosinophilia and oedema. J Endocrinol, 1983, 99: 123-30

[8] SmithDE, KronenbergMS. Effect of copper on cytoplasmic and unclear binding of 17 β-estradiol in the rat uterus. Biol Repiod, 1984, 31: 531-5

[9] OsterGK. Chemical reactions of the copper intrauterine device. Fertil Steril, 1972, 23: 18-23

[10] TchernitchinA, TchernitchinX. Characterization of the estrogen receptors in the uterine and blood eosinophil leukocytes. Experientia, 1976, 32: 1240-2