The placenta as a glucocorticoid target tissue: Exchange assay of (3H)-dexamethasone binding and effect of steroids on receptor content
Binding of (3H)-dexamethasone was studied in high speed supernatant (HSS) of basal zone trophoblast and labyrinthine zone of rat placenta using an exchange assay. The system showed the following characteristics: maximum binding was attained after 120 min of incubation; molybdate was required in the...
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1983
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| Acceso en línea: | https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_00185043_v15_n1_p41_Heller http://hdl.handle.net/20.500.12110/paper_00185043_v15_n1_p41_Heller |
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paper:paper_00185043_v15_n1_p41_Heller |
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paper:paper_00185043_v15_n1_p41_Heller2023-06-08T14:39:31Z The placenta as a glucocorticoid target tissue: Exchange assay of (3H)-dexamethasone binding and effect of steroids on receptor content corticosterone dexamethasone estradiol glucocorticoid progesterone radioisotope steroid testosterone animal cell dexamethasone h 3 dose response drug binding drug comparison drug receptor binding drug response fetus nonhuman pharmacokinetics placenta pregnancy rat target Animal Binding Sites Corticosterone Dexamethasone Estradiol Female Placenta Pregnancy Progesterone Rats Rats, Inbred Strains Receptors, Glucocorticoid Receptors, Steroid Support, Non-U.S. Gov't Testosterone Tritium Binding of (3H)-dexamethasone was studied in high speed supernatant (HSS) of basal zone trophoblast and labyrinthine zone of rat placenta using an exchange assay. The system showed the following characteristics: maximum binding was attained after 120 min of incubation; molybdate was required in the medium to measure binding sites at 20°C and equilibrium conditions; exchange was near 90-100% between ligand and corticosterone added during a preincubation; (4) low capacity (190-250 fmoles/mg protein), high affinity (K(d) 10-8 M) binders were determined by saturation analysis; competition with other steroids in vitro revealed that in basal zone trophoblast, only dexamethasone displaced the ligand, whereas in labyrinthine zone corticosterone, progesterone and testosterone competed to a smaller degree than dexamethasone. We have also studied the effect of in vivo treatment of pregnant rats for four days with dexamethasone, corticosterone, estradiol, progesterone or testosterone, on (3H)-dexamethasone binding. Of all tested compounds, only dexamethasone treatment (which was suspended 24 h before the experiment to prevent receptor occupancy by exogenous hormone) significantly decreased binding of the tritiated hormone in HSS of labyrinthine zone and basal zone trophoblast. These results suggest that dexamethasone regulates its own receptor in placenta. The physiological aspect of this phenomenon requires elucidation of the role of glucocorticoids on placental function in the rat. 1983 https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_00185043_v15_n1_p41_Heller http://hdl.handle.net/20.500.12110/paper_00185043_v15_n1_p41_Heller |
| institution |
Universidad de Buenos Aires |
| institution_str |
I-28 |
| repository_str |
R-134 |
| collection |
Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA) |
| topic |
corticosterone dexamethasone estradiol glucocorticoid progesterone radioisotope steroid testosterone animal cell dexamethasone h 3 dose response drug binding drug comparison drug receptor binding drug response fetus nonhuman pharmacokinetics placenta pregnancy rat target Animal Binding Sites Corticosterone Dexamethasone Estradiol Female Placenta Pregnancy Progesterone Rats Rats, Inbred Strains Receptors, Glucocorticoid Receptors, Steroid Support, Non-U.S. Gov't Testosterone Tritium |
| spellingShingle |
corticosterone dexamethasone estradiol glucocorticoid progesterone radioisotope steroid testosterone animal cell dexamethasone h 3 dose response drug binding drug comparison drug receptor binding drug response fetus nonhuman pharmacokinetics placenta pregnancy rat target Animal Binding Sites Corticosterone Dexamethasone Estradiol Female Placenta Pregnancy Progesterone Rats Rats, Inbred Strains Receptors, Glucocorticoid Receptors, Steroid Support, Non-U.S. Gov't Testosterone Tritium The placenta as a glucocorticoid target tissue: Exchange assay of (3H)-dexamethasone binding and effect of steroids on receptor content |
| topic_facet |
corticosterone dexamethasone estradiol glucocorticoid progesterone radioisotope steroid testosterone animal cell dexamethasone h 3 dose response drug binding drug comparison drug receptor binding drug response fetus nonhuman pharmacokinetics placenta pregnancy rat target Animal Binding Sites Corticosterone Dexamethasone Estradiol Female Placenta Pregnancy Progesterone Rats Rats, Inbred Strains Receptors, Glucocorticoid Receptors, Steroid Support, Non-U.S. Gov't Testosterone Tritium |
| description |
Binding of (3H)-dexamethasone was studied in high speed supernatant (HSS) of basal zone trophoblast and labyrinthine zone of rat placenta using an exchange assay. The system showed the following characteristics: maximum binding was attained after 120 min of incubation; molybdate was required in the medium to measure binding sites at 20°C and equilibrium conditions; exchange was near 90-100% between ligand and corticosterone added during a preincubation; (4) low capacity (190-250 fmoles/mg protein), high affinity (K(d) 10-8 M) binders were determined by saturation analysis; competition with other steroids in vitro revealed that in basal zone trophoblast, only dexamethasone displaced the ligand, whereas in labyrinthine zone corticosterone, progesterone and testosterone competed to a smaller degree than dexamethasone. We have also studied the effect of in vivo treatment of pregnant rats for four days with dexamethasone, corticosterone, estradiol, progesterone or testosterone, on (3H)-dexamethasone binding. Of all tested compounds, only dexamethasone treatment (which was suspended 24 h before the experiment to prevent receptor occupancy by exogenous hormone) significantly decreased binding of the tritiated hormone in HSS of labyrinthine zone and basal zone trophoblast. These results suggest that dexamethasone regulates its own receptor in placenta. The physiological aspect of this phenomenon requires elucidation of the role of glucocorticoids on placental function in the rat. |
| title |
The placenta as a glucocorticoid target tissue: Exchange assay of (3H)-dexamethasone binding and effect of steroids on receptor content |
| title_short |
The placenta as a glucocorticoid target tissue: Exchange assay of (3H)-dexamethasone binding and effect of steroids on receptor content |
| title_full |
The placenta as a glucocorticoid target tissue: Exchange assay of (3H)-dexamethasone binding and effect of steroids on receptor content |
| title_fullStr |
The placenta as a glucocorticoid target tissue: Exchange assay of (3H)-dexamethasone binding and effect of steroids on receptor content |
| title_full_unstemmed |
The placenta as a glucocorticoid target tissue: Exchange assay of (3H)-dexamethasone binding and effect of steroids on receptor content |
| title_sort |
placenta as a glucocorticoid target tissue: exchange assay of (3h)-dexamethasone binding and effect of steroids on receptor content |
| publishDate |
1983 |
| url |
https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_00185043_v15_n1_p41_Heller http://hdl.handle.net/20.500.12110/paper_00185043_v15_n1_p41_Heller |
| _version_ |
1768543068890333184 |