Die Wirkung intrathekaler Baclofenapplikation auf die Freisetzung von Adrenalin, Noradrenalin und Homovanillinsäure aus dem Nucleus paraventricularis hypothalami der Ratte

Abstract Introduction: In the clinical observation of patients suffering from spastic and autonomous dysregulation with hypertonia, intrathecal application of baclofen improved both symptoms. Aim: In this study we investigated the correlation of intrathecal application of baclofen, a specific GABAB ? receptor agonist, and the release of epinephrine, norepinephrine and homovanillin acid from the hypothalamic paraventricular nucleus. The study was part of a collaborative project in which dihydroxyphenylacetic acid (DOPAC), 5 ? hydroxytryptamine (5 ? HT), glutamate and aspartate were quantified while blood pressure was measured. Homovanillic acid (HVA) as a decomposition product of norepinephrine, epinephrine and dopamine was used as a parameter for the release of dopamine. The magnocellular part of the nucleus paraventricularis hypothalami has neuroendocrinological functions and its parvocellular part plays a role in the central control of autonomous functions, e.g. control of blood pressure. Method: We implanted a microdialysis probe in the nucleus paraventricularis hypothalami of 38 Wistar-Rats. In 19 animals 1.5 mg Baclofen was injected in the lateral ventricel and the equivalent quantity of ringer?s solution in the remaining 19 animals as a control group. Norepinephrine, epinephrine and the metabolite HVA were quantified by HPLC. Result: There was no significant difference between the baclofen and control group concerning the release of epinephrine and norepinephrine from the nucleus paraventricularis hypothalami. A significant increase of HVA concentration was observed in the animals treated with baclofen compared to the control group. Outlook: To prove the role of the paraventricularis hypothalamic nucleus in the control of blood pressure and the influence of baclofen on the release of epinephrine, norepinephrine and HVA further studies have to follow.Abstract Introduction: In the clinical observation of patients suffering from spastic and autonomous dysregulation with hypertonia, intrathecal application of baclofen improved both symptoms. Aim: In this study we investigated the correlation of intrathecal application of baclofen, a specific GABAB ? receptor agonist, and the release of epinephrine, norepinephrine and homovanillin acid from the hypothalamic paraventricular nucleus. The study was part of a collaborative project in which dihydroxyphenylacetic acid (DOPAC), 5 ? hydroxytryptamine (5 ? HT), glutamate and aspartate were quantified while blood pressure was measured. Homovanillic acid (HVA) as a decomposition product of norepinephrine, epinephrine and dopamine was used as a parameter for the release of dopamine. The magnocellular part of the nucleus paraventricularis hypothalami has neuroendocrinological functions and its parvocellular part plays a role in the central control of autonomous functions, e.g. control of blood pressure. Method: We implanted a microdialysis probe in the nucleus paraventricularis hypothalami of 38 Wistar-Rats. In 19 animals 1.5 mg Baclofen was injected in the lateral ventricel and the equivalent quantity of ringer?s solution in the remaining 19 animals as a control group. Norepinephrine, epinephrine and the metabolite HVA were quantified by HPLC. Result: There was no significant difference between the baclofen and control group concerning the release of epinephrine and norepinephrine from the nucleus paraventricularis hypothalami. A significant increase of HVA concentration was observed in the animals treated with baclofen compared to the control group. Outlook: To prove the role of the paraventricularis hypothalamic nucleus in the control of blood pressure and the influence of baclofen on the release of epinephrine, norepinephrine and HVA further studies have to follow.