Journal article

Cardioinhibitory actions of clonidine assessed by cardiac vagal motoneuron recordings

Emil Toader, Andrei Cividjian, Nicolas Rentero, Robin M McAllen, Luc Quintin

JOURNAL OF HYPERTENSION | LIPPINCOTT WILLIAMS & WILKINS | Published : 2008

Abstract

BACKGROUND: Cardiac vagal activity is now considered as an important therapeutic target. However, there is a lack of direct data on how cardiac vagal motoneurons respond to parasympathomimetic agents. METHODS: Rats were anesthetized with urethane and mechanically ventilated. Single-unit activity was recorded in the nucleus ambiguus from cardiac vagal motoneurons, identified by antidromic activation from the cardiac vagal branch and their barosensitivity. RESULTS: Nitroprusside lowered systolic blood pressure, increased heart rate and inhibited cardiac vagal motoneuron activity (n = 5 cells in five rats). Clonidine 1-100 microg kg(-1) intravenously, however, lowered systolic blood pressure, b..

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