Properties and distribution of glucocorticoid-binding sites in cytosol of the spinal cord

We have examined the spinal cord for the presence of glucocorticoid-binding sites. For this purpose, cytosol from the spinal cord of adrenalectomized rats was incubated with (3H)-dexamethasone. Maximal binding was obtained after 20 h of incubation at 0°C in the presence of 20 mM molybdate, whereas a...

Descripción completa

Guardado en:
Detalles Bibliográficos
Autores principales: Orti, E., Coirini, H., De Nicola, A.F.
Formato: JOUR
Materias:
rat
Acceso en línea:http://hdl.handle.net/20.500.12110/paper_00283835_v40_n3_p225_Orti
Aporte de:
id todo:paper_00283835_v40_n3_p225_Orti
record_format dspace
spelling todo:paper_00283835_v40_n3_p225_Orti2023-10-03T14:38:50Z Properties and distribution of glucocorticoid-binding sites in cytosol of the spinal cord Orti, E. Coirini, H. De Nicola, A.F. 11beta,17beta dihydroxy 17 (1 propynyl)androsta 1,4,6 trien 3 one aldosterone corticosterone dexamethasone dexamethasone h 3 estradiol glucocorticoid receptor progesterone radioisotope testosterone triamcinolone acetonide unclassified drug adrenalectomy animal cell article central nervous system drug distribution drug efficacy drug receptor binding endocrine system nonhuman ontogeny pharmacokinetics priority journal rat spinal cord We have examined the spinal cord for the presence of glucocorticoid-binding sites. For this purpose, cytosol from the spinal cord of adrenalectomized rats was incubated with (3H)-dexamethasone. Maximal binding was obtained after 20 h of incubation at 0°C in the presence of 20 mM molybdate, whereas at 20° C the maximum was at 2 h. Using a range of (3H)-dexamethasone concentrations (0.2-30 nM), low capacity (161 ± 23 fmol/g protein) and high affinity (K(d) 3.2 ± 0.3 nM) sites were measured. Binding sites decreased by 25% and K(d) increased 2.5-fold after incubation with a pure glucocorticoid (RU 26988). Relative binding affinities of several competitors of 10 nM (3H)-dexamethasone were: triamcinolone acetonide 108, dexamethasone 100, RU 26988 54, corticosterone 18, progesterone 17, aldosterone 7, estradiol and testosterone < 1. Sedimentation coefficients in glycerol gradients containing molybdate were in the range of those published for glucocorticoid receptors (9.6-9.8 S). Binding of (3H)-dexamethasone was decreased by omitting a SH-protective agent from the buffer or by addition of SH-blocking reagents such as N-ethylmaleimide and p-chloromercuribenzoate. Using rats of different ages, it was found that binding sites were much lower in spinal cord from 2- to 8-day-old rats than in rats of 13-20 days and adults. Regional distribution studies using cytosol from spinal cords dissected between vertebrae C1-C2, C3-C7, T1-T8, T9-L3 and L4-L6 revealed that binding sites were higher in regions containing the cervical (C3-C7) and lumbar (T9-L3) enlargements, with respect to L4-L6. These studies suggest that the spinal cord contains cytosolic-binding sites resembling glucocorticoid receptors, and that the reported action of these steroids on spinal cord function could be mediated by these sites. JOUR info:eu-repo/semantics/openAccess http://creativecommons.org/licenses/by/2.5/ar http://hdl.handle.net/20.500.12110/paper_00283835_v40_n3_p225_Orti
institution Universidad de Buenos Aires
institution_str I-28
repository_str R-134
collection Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA)
topic 11beta,17beta dihydroxy 17 (1 propynyl)androsta 1,4,6 trien 3 one
aldosterone
corticosterone
dexamethasone
dexamethasone h 3
estradiol
glucocorticoid receptor
progesterone
radioisotope
testosterone
triamcinolone acetonide
unclassified drug
adrenalectomy
animal cell
article
central nervous system
drug distribution
drug efficacy
drug receptor binding
endocrine system
nonhuman
ontogeny
pharmacokinetics
priority journal
rat
spinal cord
spellingShingle 11beta,17beta dihydroxy 17 (1 propynyl)androsta 1,4,6 trien 3 one
aldosterone
corticosterone
dexamethasone
dexamethasone h 3
estradiol
glucocorticoid receptor
progesterone
radioisotope
testosterone
triamcinolone acetonide
unclassified drug
adrenalectomy
animal cell
article
central nervous system
drug distribution
drug efficacy
drug receptor binding
endocrine system
nonhuman
ontogeny
pharmacokinetics
priority journal
rat
spinal cord
Orti, E.
Coirini, H.
De Nicola, A.F.
Properties and distribution of glucocorticoid-binding sites in cytosol of the spinal cord
topic_facet 11beta,17beta dihydroxy 17 (1 propynyl)androsta 1,4,6 trien 3 one
aldosterone
corticosterone
dexamethasone
dexamethasone h 3
estradiol
glucocorticoid receptor
progesterone
radioisotope
testosterone
triamcinolone acetonide
unclassified drug
adrenalectomy
animal cell
article
central nervous system
drug distribution
drug efficacy
drug receptor binding
endocrine system
nonhuman
ontogeny
pharmacokinetics
priority journal
rat
spinal cord
description We have examined the spinal cord for the presence of glucocorticoid-binding sites. For this purpose, cytosol from the spinal cord of adrenalectomized rats was incubated with (3H)-dexamethasone. Maximal binding was obtained after 20 h of incubation at 0°C in the presence of 20 mM molybdate, whereas at 20° C the maximum was at 2 h. Using a range of (3H)-dexamethasone concentrations (0.2-30 nM), low capacity (161 ± 23 fmol/g protein) and high affinity (K(d) 3.2 ± 0.3 nM) sites were measured. Binding sites decreased by 25% and K(d) increased 2.5-fold after incubation with a pure glucocorticoid (RU 26988). Relative binding affinities of several competitors of 10 nM (3H)-dexamethasone were: triamcinolone acetonide 108, dexamethasone 100, RU 26988 54, corticosterone 18, progesterone 17, aldosterone 7, estradiol and testosterone < 1. Sedimentation coefficients in glycerol gradients containing molybdate were in the range of those published for glucocorticoid receptors (9.6-9.8 S). Binding of (3H)-dexamethasone was decreased by omitting a SH-protective agent from the buffer or by addition of SH-blocking reagents such as N-ethylmaleimide and p-chloromercuribenzoate. Using rats of different ages, it was found that binding sites were much lower in spinal cord from 2- to 8-day-old rats than in rats of 13-20 days and adults. Regional distribution studies using cytosol from spinal cords dissected between vertebrae C1-C2, C3-C7, T1-T8, T9-L3 and L4-L6 revealed that binding sites were higher in regions containing the cervical (C3-C7) and lumbar (T9-L3) enlargements, with respect to L4-L6. These studies suggest that the spinal cord contains cytosolic-binding sites resembling glucocorticoid receptors, and that the reported action of these steroids on spinal cord function could be mediated by these sites.
format JOUR
author Orti, E.
Coirini, H.
De Nicola, A.F.
author_facet Orti, E.
Coirini, H.
De Nicola, A.F.
author_sort Orti, E.
title Properties and distribution of glucocorticoid-binding sites in cytosol of the spinal cord
title_short Properties and distribution of glucocorticoid-binding sites in cytosol of the spinal cord
title_full Properties and distribution of glucocorticoid-binding sites in cytosol of the spinal cord
title_fullStr Properties and distribution of glucocorticoid-binding sites in cytosol of the spinal cord
title_full_unstemmed Properties and distribution of glucocorticoid-binding sites in cytosol of the spinal cord
title_sort properties and distribution of glucocorticoid-binding sites in cytosol of the spinal cord
url http://hdl.handle.net/20.500.12110/paper_00283835_v40_n3_p225_Orti
work_keys_str_mv AT ortie propertiesanddistributionofglucocorticoidbindingsitesincytosolofthespinalcord
AT coirinih propertiesanddistributionofglucocorticoidbindingsitesincytosolofthespinalcord
AT denicolaaf propertiesanddistributionofglucocorticoidbindingsitesincytosolofthespinalcord
_version_ 1782024825960660992