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The Effect on Vasopressin Release of Microinjection of Cholinergic Agonists into the Paraventricular Nucleus of Conscious Rats
Author(s) -
Shoji Masaru,
Share Leonard,
Crofton Joan T.,
Brooks David P.
Publication year - 1989
Publication title -
journal of neuroendocrinology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.062
H-Index - 116
eISSN - 1365-2826
pISSN - 0953-8194
DOI - 10.1111/j.1365-2826.1989.tb00138.x
Subject(s) - endocrinology , medicine , vasopressin , oxotremorine , microinjection , muscarinic acetylcholine receptor , chemistry , cholinergic , agonist , vasopressin antagonists , receptor , antagonist
We have studied in conscious unrestrained rats under basal conditions the effect of activation of muscarinic and nicotinic receptors in the paraventricular nucleus on vasopressin secretion and mean arterial blood pressure. The microinjection of oxotremorine (0.2, 2 or 20 ng), a specific muscarinic agonist, produced a substantial, dose‐dependent, transient increase in the plasma vasopressin concentration. There was also a rise in mean arterial blood pressure and a bradycardia that followed the same time‐course as the change in plasma vasopressin levels. The microinjection of nicotine (0.1, 1 or 10 HQ) into the paraventricular nucleus had only questionable effects on vasopressin release and mean arterial blood pressure; heart rate was unaffected. These findings suggest that muscarinic receptors may be of primary importance in the paraventricular nucleus in the Cholinergic stimulation of vasopressin release.