Superior cervical ganglionectomy depresses norepinephrine uptake, increases the density of α-adrenoceptor sites, and induces supersensitivity to adrenergic drugs in rat medial basal hypothalamus
The occurrence of nonpineal mediated effects of superior cervical ganglionectomy (SCGx) on neuroendocrine function prompted us to study SCGx effects on medial basal hypothalamic (MBH) norepinephrine (NE) content and uptake, and on MBH α- and β-adrenoceptor sites assessed by 3H-dihydroergocryptine an...
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todo:paper_00283835_v33_n4_p199_Cardinali2023-10-03T14:38:48Z Superior cervical ganglionectomy depresses norepinephrine uptake, increases the density of α-adrenoceptor sites, and induces supersensitivity to adrenergic drugs in rat medial basal hypothalamus Cardinali, D.P. Vacas, M.I. Luchelli Defortis, A. Stefano, F.J.E. Adrenoceptors Medial basal hypothalamus Norepinephrine Pineal gland Superior cervical ganglion Tubulin adrenergic receptor stimulating agent alpha adrenergic receptor isoprenaline levodopa noradrenalin phentolamine propranolol radioisotope animal experiment autonomic nervous system basal hypothalamus colchicine h 3 dihydroalprenolol h 3 dihydroergocryptine h 3 dose response drug response hypothalamus noradrenalin h 3 pineal body rat superior cervical ganglionectomy supersensitivity Animal Dihydroalprenolol Ganglia, Sympathetic Hypothalamus Isoproterenol Kinetics Levodopa Male Norepinephrine Phentolamine Propranolol Rats Rats, Inbred Strains Receptors, Adrenergic Receptors, Adrenergic, alpha Support, Non-U.S. Gov't Tubulin The occurrence of nonpineal mediated effects of superior cervical ganglionectomy (SCGx) on neuroendocrine function prompted us to study SCGx effects on medial basal hypothalamic (MBH) norepinephrine (NE) content and uptake, and on MBH α- and β-adrenoceptor sites assessed by 3H-dihydroergocryptine and 3H-dihydroalprenolol binding. SCGx depressed MBH NE uptake but did not affect NE content in MBH homogenates. After SCGx, a significant 35% increase of α-adrenoceptor sites occurred in MBH whereas the β-adrenoceptors remained unchanged. In order to correlate the increase of binding sites with adrenoceptor-mediated supersensitive responses in MBH, the effects on NE, isoprotere-nol or L-dihydroxyphenylalanine (L-dopa) on MBH tubulin concentration were assessed. Each drug brought about a greater depression of MBH tubulin in SCGx than in control rats. A dose-response study of the MBH tubulin decrease after L-dopa treatment indicated that SCGx augmented the potency of L-dopa by 2.5-fold, shifting the dose-response curve to the left in a parallel manner. Such increase in potency was only 1.6-fold when SCGx was associated with Px. SCGx increased both α- and β-adrenoceptor sensitivity of MBH tubulin. Px, while leaving the α-adrenoceptor supersensitive response unmodified, removed the β-adrenoceptor-mediated effect on tubulin because: (i) isoproterenol injection did not affect MBH tubulin in SCGx-Px rats; (ii) NE or L-dopa induced a depression of MBH tubulin which was partially impaired by propranolol in SCGx rats and was refractory to β-adrenergic blockade in SCGx-Px animals; (iii) the α-adrenergic blocker phentolamine abolished effectively NE or L-dopa effect on MBH tubulin in SCGx-Px rats but not in SCGx rats. Dose-related decreases of cerebral cortex tubulin after L-dopa treatment were essentially similar in SCGx, SCGx-Px or sham-operated rats. These results indicate that SCGx depresses NE uptake and increases α-adrenoceptor sites in MBH as well as the adrenoceptor-mediated response of MBH tubulin. A functionally relevant link between superior cervical ganglia and MBH appears to occur in the rat. © 1981 S. Karger AG, Basel. JOUR info:eu-repo/semantics/openAccess http://creativecommons.org/licenses/by/2.5/ar http://hdl.handle.net/20.500.12110/paper_00283835_v33_n4_p199_Cardinali |
| institution |
Universidad de Buenos Aires |
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I-28 |
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R-134 |
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Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA) |
| topic |
Adrenoceptors Medial basal hypothalamus Norepinephrine Pineal gland Superior cervical ganglion Tubulin adrenergic receptor stimulating agent alpha adrenergic receptor isoprenaline levodopa noradrenalin phentolamine propranolol radioisotope animal experiment autonomic nervous system basal hypothalamus colchicine h 3 dihydroalprenolol h 3 dihydroergocryptine h 3 dose response drug response hypothalamus noradrenalin h 3 pineal body rat superior cervical ganglionectomy supersensitivity Animal Dihydroalprenolol Ganglia, Sympathetic Hypothalamus Isoproterenol Kinetics Levodopa Male Norepinephrine Phentolamine Propranolol Rats Rats, Inbred Strains Receptors, Adrenergic Receptors, Adrenergic, alpha Support, Non-U.S. Gov't Tubulin |
| spellingShingle |
Adrenoceptors Medial basal hypothalamus Norepinephrine Pineal gland Superior cervical ganglion Tubulin adrenergic receptor stimulating agent alpha adrenergic receptor isoprenaline levodopa noradrenalin phentolamine propranolol radioisotope animal experiment autonomic nervous system basal hypothalamus colchicine h 3 dihydroalprenolol h 3 dihydroergocryptine h 3 dose response drug response hypothalamus noradrenalin h 3 pineal body rat superior cervical ganglionectomy supersensitivity Animal Dihydroalprenolol Ganglia, Sympathetic Hypothalamus Isoproterenol Kinetics Levodopa Male Norepinephrine Phentolamine Propranolol Rats Rats, Inbred Strains Receptors, Adrenergic Receptors, Adrenergic, alpha Support, Non-U.S. Gov't Tubulin Cardinali, D.P. Vacas, M.I. Luchelli Defortis, A. Stefano, F.J.E. Superior cervical ganglionectomy depresses norepinephrine uptake, increases the density of α-adrenoceptor sites, and induces supersensitivity to adrenergic drugs in rat medial basal hypothalamus |
| topic_facet |
Adrenoceptors Medial basal hypothalamus Norepinephrine Pineal gland Superior cervical ganglion Tubulin adrenergic receptor stimulating agent alpha adrenergic receptor isoprenaline levodopa noradrenalin phentolamine propranolol radioisotope animal experiment autonomic nervous system basal hypothalamus colchicine h 3 dihydroalprenolol h 3 dihydroergocryptine h 3 dose response drug response hypothalamus noradrenalin h 3 pineal body rat superior cervical ganglionectomy supersensitivity Animal Dihydroalprenolol Ganglia, Sympathetic Hypothalamus Isoproterenol Kinetics Levodopa Male Norepinephrine Phentolamine Propranolol Rats Rats, Inbred Strains Receptors, Adrenergic Receptors, Adrenergic, alpha Support, Non-U.S. Gov't Tubulin |
| description |
The occurrence of nonpineal mediated effects of superior cervical ganglionectomy (SCGx) on neuroendocrine function prompted us to study SCGx effects on medial basal hypothalamic (MBH) norepinephrine (NE) content and uptake, and on MBH α- and β-adrenoceptor sites assessed by 3H-dihydroergocryptine and 3H-dihydroalprenolol binding. SCGx depressed MBH NE uptake but did not affect NE content in MBH homogenates. After SCGx, a significant 35% increase of α-adrenoceptor sites occurred in MBH whereas the β-adrenoceptors remained unchanged. In order to correlate the increase of binding sites with adrenoceptor-mediated supersensitive responses in MBH, the effects on NE, isoprotere-nol or L-dihydroxyphenylalanine (L-dopa) on MBH tubulin concentration were assessed. Each drug brought about a greater depression of MBH tubulin in SCGx than in control rats. A dose-response study of the MBH tubulin decrease after L-dopa treatment indicated that SCGx augmented the potency of L-dopa by 2.5-fold, shifting the dose-response curve to the left in a parallel manner. Such increase in potency was only 1.6-fold when SCGx was associated with Px. SCGx increased both α- and β-adrenoceptor sensitivity of MBH tubulin. Px, while leaving the α-adrenoceptor supersensitive response unmodified, removed the β-adrenoceptor-mediated effect on tubulin because: (i) isoproterenol injection did not affect MBH tubulin in SCGx-Px rats; (ii) NE or L-dopa induced a depression of MBH tubulin which was partially impaired by propranolol in SCGx rats and was refractory to β-adrenergic blockade in SCGx-Px animals; (iii) the α-adrenergic blocker phentolamine abolished effectively NE or L-dopa effect on MBH tubulin in SCGx-Px rats but not in SCGx rats. Dose-related decreases of cerebral cortex tubulin after L-dopa treatment were essentially similar in SCGx, SCGx-Px or sham-operated rats. These results indicate that SCGx depresses NE uptake and increases α-adrenoceptor sites in MBH as well as the adrenoceptor-mediated response of MBH tubulin. A functionally relevant link between superior cervical ganglia and MBH appears to occur in the rat. © 1981 S. Karger AG, Basel. |
| format |
JOUR |
| author |
Cardinali, D.P. Vacas, M.I. Luchelli Defortis, A. Stefano, F.J.E. |
| author_facet |
Cardinali, D.P. Vacas, M.I. Luchelli Defortis, A. Stefano, F.J.E. |
| author_sort |
Cardinali, D.P. |
| title |
Superior cervical ganglionectomy depresses norepinephrine uptake, increases the density of α-adrenoceptor sites, and induces supersensitivity to adrenergic drugs in rat medial basal hypothalamus |
| title_short |
Superior cervical ganglionectomy depresses norepinephrine uptake, increases the density of α-adrenoceptor sites, and induces supersensitivity to adrenergic drugs in rat medial basal hypothalamus |
| title_full |
Superior cervical ganglionectomy depresses norepinephrine uptake, increases the density of α-adrenoceptor sites, and induces supersensitivity to adrenergic drugs in rat medial basal hypothalamus |
| title_fullStr |
Superior cervical ganglionectomy depresses norepinephrine uptake, increases the density of α-adrenoceptor sites, and induces supersensitivity to adrenergic drugs in rat medial basal hypothalamus |
| title_full_unstemmed |
Superior cervical ganglionectomy depresses norepinephrine uptake, increases the density of α-adrenoceptor sites, and induces supersensitivity to adrenergic drugs in rat medial basal hypothalamus |
| title_sort |
superior cervical ganglionectomy depresses norepinephrine uptake, increases the density of α-adrenoceptor sites, and induces supersensitivity to adrenergic drugs in rat medial basal hypothalamus |
| url |
http://hdl.handle.net/20.500.12110/paper_00283835_v33_n4_p199_Cardinali |
| work_keys_str_mv |
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