Vasopressin regulation of noradrenaline release within the supraoptic nucleus.
The effect of electrically evoked dendritic vasopressin release on noradrenaline release into the hypothalamic supraoptic nucleus was assessed by in vivo microdialysis in conjunction with high pressure liquid chromatography and electrochemical detection. Electrical activation of magnocellular supraoptic neurones by stimulation of their axons at the level of the neural lobe significantly increased noradrenaline release into the nucleus (2.5-fold, P<0.03). This increase was completely blocked by administration of a nonpeptide vasopressin V1a receptor antagonist via the microdialysis probe. These data suggest that dendritically released vasopressin facilitates noradrenaline release into the hypothalamic nucleus.
Ludwig
M
M
Department of Biomedical Sciences, University of Edinburgh Medical School, Edinburgh, UK. mike.ludwig@ed.ac.uk
Onaka
T
T
Yagi
K
K
D065092:Antidiuretic Hormone Receptor Antagonists; D002851:Chromatography, High Pressure Liquid; D004563:Electrochemistry; D009474:Neurons / Q000187:drug effects / Q000502:physiology; D009638:Norepinephrine / Q000378:metabolism*; D010880:Piperidines / Q000494:pharmacology; D011188:Potassium / Q000494:pharmacology; D015363:Quinolones / Q000494:pharmacology; D013495:Supraoptic Nucleus / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D014667:Vasopressins / Q000502:physiology*
D065092:Antidiuretic Hormone Receptor Antagonists; D010880:Piperidines; D015363:Quinolones; D014667:Vasopressins; C068644:OPC 21268; D011188:Potassium; D009638:Norepinephrine