title: Acetylcholine-induced vasodilatation in the human hypertensive kidney: inhibition by muscarinic receptor antagonism.
abstract: OBJECTIVE
  To evaluate the vascular response of the human hypertensive kidney to endothelial stimulation with acetylcholine (ACh) and to assess whether this effect can be inhibited by the non-specific muscarinic receptor antagonist atropine.
  
  
  METHODS
  Three stepwise increasing doses of ACh (0.3, 1.0 and 3.0 microg/kg per min) in combination either with placebo or with 100 or 300 ng/kg per min atropine were infused into the right renal artery of 20 hypertensive patients. Renal blood flow was determined using the 133Xe wash-out technique.
  
  
  RESULTS
  Infusion of ACh induced a dose-dependent increase in renal blood flow (P= 0.02). Both doses of atropine attenuated the ACh-induced renal vasodilatation (P < 0.05).
  
  
  CONCLUSIONS
  Administration of ACh to the human hypertensive kidney induces a dose-dependent increase in renal blood flow. This effect is, at least partially, mediated by muscarinic receptors.
authors.affiliation: Department of Internal Medicine, University Hospital Maastricht, The Netherlands.
authors.forename: T K
authors.initials: TK
authors.lastname: Wierema
authors.forename: A J
authors.initials: AJ
authors.lastname: Houben
authors.forename: P W
authors.initials: PW
authors.lastname: de Leeuw
mesh_terms: D000109:Acetylcholine / Q000008:administration & dosage / Q000037:antagonists & inhibitors / Q000494:pharmacology*; D000328:Adult; D001285:Atropine / Q000008:administration & dosage / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D004338:Drug Combinations; D005260:Female; D006801:Humans; D006977:Hypertension, Renal / Q000503:physiopathology*; D007261:Infusions, Intra-Arterial; D007668:Kidney / Q000098:blood supply*; D008297:Male; D008875:Middle Aged; D018727:Muscarinic Antagonists / Q000008:administration & dosage / Q000494:pharmacology*; D011976:Receptors, Muscarinic / Q000502:physiology; D012079:Renal Circulation / Q000502:physiology*; D014664:Vasodilation / Q000187:drug effects*
chemical_list: D004338:Drug Combinations; D018727:Muscarinic Antagonists; D011976:Receptors, Muscarinic; D001285:Atropine; D000109:Acetylcholine