Binding and effects of catecholestrogens on adenylate cyclase activity, and adrenoceptors, benzodiazepine and GABA receptors in guinea-pig hypothalamic membranes
Catecholestrogen (CE) binding to guinea-pig hypothalamic membranes was assessed by using [3H]2-hydroxyestrone (2-OHE2) as a ligand. Binding was maximal at pH 7.4 and 37°C, and after 10 min incubations. A high affinity binding site with dissociation constant (KD) = 0.20 ± 0.02 nM and site concentrati...
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1986
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| Acceso en línea: | https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_00142999_v129_n1-2_p1_Etchegoyen http://hdl.handle.net/20.500.12110/paper_00142999_v129_n1-2_p1_Etchegoyen |
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paper:paper_00142999_v129_n1-2_p1_Etchegoyen |
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paper:paper_00142999_v129_n1-2_p1_Etchegoyen2023-06-08T14:36:50Z Binding and effects of catecholestrogens on adenylate cyclase activity, and adrenoceptors, benzodiazepine and GABA receptors in guinea-pig hypothalamic membranes Adenylate cyclase Adrenoceptor binding Benzodiazepine binding Catecholestrogens GABAergic binding Hypothalamus 2 hydroxyestradiol 2 hydroxyestrone 2 hydroxyestrone h 3 4 aminobutyric acid h 3 4 aminobutyric acid receptor adenylate cyclase adrenalin alpha adrenergic receptor benzodiazepine receptor beta adrenergic receptor catechol estrogen dihydroalprenolol h 3 dihydroergocryptine h 3 domperidone dopamine estradiol estrone flunitrazepam h 3 noradrenalin phentolamine propranolol radioisotope unclassified drug animal cell article central nervous system drug binding drug receptor binding guinea pig hypothalamus nervous system nonhuman pharmacokinetics priority journal synaptosome Adenylate Cyclase Animals Binding, Competitive Cell Membrane Enzyme Activation Estrogens, Catechol Guinea Pigs Hypothalamus Norepinephrine Receptors, Adrenergic Receptors, GABA-A Catecholestrogen (CE) binding to guinea-pig hypothalamic membranes was assessed by using [3H]2-hydroxyestrone (2-OHE2) as a ligand. Binding was maximal at pH 7.4 and 37°C, and after 10 min incubations. A high affinity binding site with dissociation constant (KD) = 0.20 ± 0.02 nM and site concentration (Bmax) = 38 ± 2 fmol/mg protein, and a low affinity binding site with KD = 235 ± 10 nM and Bmax = 4.2 ± 1.0 pmol/mg protein (n = 7) were detected. The order of affinity (Ki, μM) for displacement of 10 nM [3H]2-OHE1 from hypothalamic binding sites was 2-OHE1 (0.8), 2-hydroxyestradiol (2-OHE2) (1.0), epinephrine (5.9), norepinephrine (NE) (7.7), dopamine (270), estradiol, estrone, propranolol, phentolamine, domperidone (>10 000). NE inhibition of 2-OHE1 binding was non-competitive, Only 0.5 mM 2-OHE2 depressed in a non-competitive way the hypothalamic β-adrenoceptor binding (measured by using [3H]dihydroalprenolol) without affecting α-adrenoceptor binding (measured by using [3H]dihydroergocryptine). Both 2-OHE2 and 2-OHE1 impaired NE-stimulated adenylate cyclase activity in hypothalamic membranes with EC50 of about 5 and 10 μM, respectively. CE decreased [3H]γ-aminobutyric acid binding by hypothalamic membranes with Ki = 8 μM (2-OHE2) and 50 μM (2-OHE1). The binding of [3H]flunitrazepam to the same membrane preparation was not affected by CE. These results support the existence of significant CE binding and effects in guinea-pig hypothalamic membranes. © 1986. 1986 https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_00142999_v129_n1-2_p1_Etchegoyen http://hdl.handle.net/20.500.12110/paper_00142999_v129_n1-2_p1_Etchegoyen |
| institution |
Universidad de Buenos Aires |
| institution_str |
I-28 |
| repository_str |
R-134 |
| collection |
Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA) |
| topic |
Adenylate cyclase Adrenoceptor binding Benzodiazepine binding Catecholestrogens GABAergic binding Hypothalamus 2 hydroxyestradiol 2 hydroxyestrone 2 hydroxyestrone h 3 4 aminobutyric acid h 3 4 aminobutyric acid receptor adenylate cyclase adrenalin alpha adrenergic receptor benzodiazepine receptor beta adrenergic receptor catechol estrogen dihydroalprenolol h 3 dihydroergocryptine h 3 domperidone dopamine estradiol estrone flunitrazepam h 3 noradrenalin phentolamine propranolol radioisotope unclassified drug animal cell article central nervous system drug binding drug receptor binding guinea pig hypothalamus nervous system nonhuman pharmacokinetics priority journal synaptosome Adenylate Cyclase Animals Binding, Competitive Cell Membrane Enzyme Activation Estrogens, Catechol Guinea Pigs Hypothalamus Norepinephrine Receptors, Adrenergic Receptors, GABA-A |
| spellingShingle |
Adenylate cyclase Adrenoceptor binding Benzodiazepine binding Catecholestrogens GABAergic binding Hypothalamus 2 hydroxyestradiol 2 hydroxyestrone 2 hydroxyestrone h 3 4 aminobutyric acid h 3 4 aminobutyric acid receptor adenylate cyclase adrenalin alpha adrenergic receptor benzodiazepine receptor beta adrenergic receptor catechol estrogen dihydroalprenolol h 3 dihydroergocryptine h 3 domperidone dopamine estradiol estrone flunitrazepam h 3 noradrenalin phentolamine propranolol radioisotope unclassified drug animal cell article central nervous system drug binding drug receptor binding guinea pig hypothalamus nervous system nonhuman pharmacokinetics priority journal synaptosome Adenylate Cyclase Animals Binding, Competitive Cell Membrane Enzyme Activation Estrogens, Catechol Guinea Pigs Hypothalamus Norepinephrine Receptors, Adrenergic Receptors, GABA-A Binding and effects of catecholestrogens on adenylate cyclase activity, and adrenoceptors, benzodiazepine and GABA receptors in guinea-pig hypothalamic membranes |
| topic_facet |
Adenylate cyclase Adrenoceptor binding Benzodiazepine binding Catecholestrogens GABAergic binding Hypothalamus 2 hydroxyestradiol 2 hydroxyestrone 2 hydroxyestrone h 3 4 aminobutyric acid h 3 4 aminobutyric acid receptor adenylate cyclase adrenalin alpha adrenergic receptor benzodiazepine receptor beta adrenergic receptor catechol estrogen dihydroalprenolol h 3 dihydroergocryptine h 3 domperidone dopamine estradiol estrone flunitrazepam h 3 noradrenalin phentolamine propranolol radioisotope unclassified drug animal cell article central nervous system drug binding drug receptor binding guinea pig hypothalamus nervous system nonhuman pharmacokinetics priority journal synaptosome Adenylate Cyclase Animals Binding, Competitive Cell Membrane Enzyme Activation Estrogens, Catechol Guinea Pigs Hypothalamus Norepinephrine Receptors, Adrenergic Receptors, GABA-A |
| description |
Catecholestrogen (CE) binding to guinea-pig hypothalamic membranes was assessed by using [3H]2-hydroxyestrone (2-OHE2) as a ligand. Binding was maximal at pH 7.4 and 37°C, and after 10 min incubations. A high affinity binding site with dissociation constant (KD) = 0.20 ± 0.02 nM and site concentration (Bmax) = 38 ± 2 fmol/mg protein, and a low affinity binding site with KD = 235 ± 10 nM and Bmax = 4.2 ± 1.0 pmol/mg protein (n = 7) were detected. The order of affinity (Ki, μM) for displacement of 10 nM [3H]2-OHE1 from hypothalamic binding sites was 2-OHE1 (0.8), 2-hydroxyestradiol (2-OHE2) (1.0), epinephrine (5.9), norepinephrine (NE) (7.7), dopamine (270), estradiol, estrone, propranolol, phentolamine, domperidone (>10 000). NE inhibition of 2-OHE1 binding was non-competitive, Only 0.5 mM 2-OHE2 depressed in a non-competitive way the hypothalamic β-adrenoceptor binding (measured by using [3H]dihydroalprenolol) without affecting α-adrenoceptor binding (measured by using [3H]dihydroergocryptine). Both 2-OHE2 and 2-OHE1 impaired NE-stimulated adenylate cyclase activity in hypothalamic membranes with EC50 of about 5 and 10 μM, respectively. CE decreased [3H]γ-aminobutyric acid binding by hypothalamic membranes with Ki = 8 μM (2-OHE2) and 50 μM (2-OHE1). The binding of [3H]flunitrazepam to the same membrane preparation was not affected by CE. These results support the existence of significant CE binding and effects in guinea-pig hypothalamic membranes. © 1986. |
| title |
Binding and effects of catecholestrogens on adenylate cyclase activity, and adrenoceptors, benzodiazepine and GABA receptors in guinea-pig hypothalamic membranes |
| title_short |
Binding and effects of catecholestrogens on adenylate cyclase activity, and adrenoceptors, benzodiazepine and GABA receptors in guinea-pig hypothalamic membranes |
| title_full |
Binding and effects of catecholestrogens on adenylate cyclase activity, and adrenoceptors, benzodiazepine and GABA receptors in guinea-pig hypothalamic membranes |
| title_fullStr |
Binding and effects of catecholestrogens on adenylate cyclase activity, and adrenoceptors, benzodiazepine and GABA receptors in guinea-pig hypothalamic membranes |
| title_full_unstemmed |
Binding and effects of catecholestrogens on adenylate cyclase activity, and adrenoceptors, benzodiazepine and GABA receptors in guinea-pig hypothalamic membranes |
| title_sort |
binding and effects of catecholestrogens on adenylate cyclase activity, and adrenoceptors, benzodiazepine and gaba receptors in guinea-pig hypothalamic membranes |
| publishDate |
1986 |
| url |
https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_00142999_v129_n1-2_p1_Etchegoyen http://hdl.handle.net/20.500.12110/paper_00142999_v129_n1-2_p1_Etchegoyen |
| _version_ |
1768544714154311680 |