title: Dehydration-induced vasopressin secretion in humans: involvement of the histaminergic system.
abstract: In rats, the hypothalamic neurotransmitter histamine participates in regulation of vasopressin secretion and seems to be of physiological importance, because blockade of the histaminergic system reduces dehydration-induced vasopressin secretion. We investigated whether histamine is also involved in regulation of vasopressin secretion during dehydration in humans. We found that 40 h of dehydration gradually increased plasma osmolality by 10 mosmol/kg and induced a fourfold increase in vasopressin levels. Pretreatment with the H(2)-receptor antagonists cimetidine or ranitidine significantly reduced the dehydration-induced increase in vasopressin levels approximately 40% after 34 and 37 h of dehydration, whereas this was not the case with the H(1)-receptor antagonist mepyramine. Dehydration reduced aldosterone secretion by approximately 50%. This effect of dehydration was reduced by both H(1)- and H(2)-receptor blockade after 16 and/or 34 h of dehydration. We conclude that vasopressin secretion in response to dehydration in humans is under the regulatory influence of histamine and that the effect seems to be mediated via H(2)-receptors. In addition, the regulation of aldosterone secretion during dehydration also seems to involve the histaminergic system via H(1) and H(2) receptors.
authors.affiliation: Department of Medical Physiology, Division of Endocrinology and Metabolism, The Panum Institute, Rigshospitalet, University of Copenhagen, DK-2200 Copenhagen N, Denmark. kjaer@mfi.ku.dk
authors.forename: A
authors.initials: A
authors.lastname: Kjaer
authors.forename: U
authors.initials: U
authors.lastname: Knigge
authors.forename: H
authors.initials: H
authors.lastname: Jørgensen
authors.forename: J
authors.initials: J
authors.lastname: Warberg
mesh_terms: D000328:Adult; D000450:Aldosterone / Q000378:metabolism; D002927:Cimetidine / Q000008:administration & dosage; D018592:Cross-Over Studies; D003681:Dehydration / Q000378:metabolism*; D004311:Double-Blind Method; D006634:Histamine H1 Antagonists / Q000008:administration & dosage; D006635:Histamine H2 Antagonists / Q000008:administration & dosage; D006801:Humans; D008297:Male; D009994:Osmolar Concentration; D010919:Placebos; D011738:Pyrilamine / Q000008:administration & dosage; D011899:Ranitidine / Q000008:administration & dosage; D011969:Receptors, Histamine H1 / Q000378:metabolism*; D011970:Receptors, Histamine H2 / Q000378:metabolism*; D014667:Vasopressins / Q000378:metabolism*; D014882:Water-Electrolyte Balance / Q000187:drug effects / Q000502:physiology
chemical_list: D006634:Histamine H1 Antagonists; D006635:Histamine H2 Antagonists; D010919:Placebos; D011969:Receptors, Histamine H1; D011970:Receptors, Histamine H2; D014667:Vasopressins; D000450:Aldosterone; D002927:Cimetidine; D011899:Ranitidine; D011738:Pyrilamine