Acetylcholine-induced vasodilatation in the human hypertensive kidney: inhibition by muscarinic receptor antagonism.

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. PATIENTS AND 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.

RCT Entities:   Population Interventions Outcomes