Alpha-1-Noradrenergic Inhibition of Growth Hormone Secretion Is Mediated through the Paraventricular Hypothalamic Nucleus in Male Rats
| Autor: | Françoise Mounier, Claude Kordon, Dominique Durand, Marie-Thérèse Bluet-Pajot, Jacques Epelbaum |
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| Rok vydání: | 1994 |
| Předmět: |
Male
Agonist endocrine system medicine.medical_specialty medicine.drug_class Endocrinology Diabetes and Metabolism Population Alpha (ethology) Biology Methoxamine Norepinephrine Cellular and Molecular Neuroscience Endocrinology Reference Values Internal medicine medicine Prazosin Animals Rats Wistar education Adrenergic alpha-Antagonists education.field_of_study Endocrine and Autonomic Systems digestive oral and skin physiology Receptors Adrenergic alpha Growth hormone secretion Rats nervous system Hypothalamus Growth Hormone Locus coeruleus Adrenergic alpha-Agonists hormones hormone substitutes and hormone antagonists Paraventricular Hypothalamic Nucleus medicine.drug |
| Zdroj: | Neuroendocrinology. 59:29-34 |
| ISSN: | 1423-0194 0028-3835 |
| DOI: | 10.1159/000126634 |
| Popis: | In the present work we investigated a possible role of an alpha 1-noradrenergic (NA) pathway involving the hypothalamic paraventricular nucleus (PVN) in the central regulation of growth hormone (GH) release. A week after bilateral electrolytic lesions of the PVN, pulsatile GH-secretory patterns were monitored in unanesthetized, freely moving control or lesioned male rats. While the pulsatility of GH secretion was maintained, the amplitude of the pulses and the area under the curve during an 8-hour sampling period were twice as high in PVN-lesioned than in control rats. Trough levels of GH were similar in the two groups. Inactivation of PVN alpha 1-receptors by local infusion of an alpha 1-NA antagonist, prazosin (50 ng/rat), also induced an increase in GH release. In control animals, intravenous injection of the alpha 1-NA agonist methoxamine (0.02 mg/100 g body weight) elicited a decrease in GH release but was ineffective when administered to PVN-lesioned rats. These data show that alpha 1-NA receptors, mediating GH inhibition, are located in the PVN. In light of the analogous effects observed herein on PVN-lesioned animals and, previously, after locus coeruleus (LC) lesions it is suggested that GH inhibition by the LC is relayed by the PVN via a local alpha 1-receptor population. |
| Databáze: | OpenAIRE |
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