Premium
Effects of quinpirole on autonomic nervous control of heart rate in rats
Author(s) -
Roquebert J.,
Moran A.,
Sauvage MF,
Demichel P.
Publication year - 1992
Publication title -
fundamental and clinical pharmacology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.655
H-Index - 73
eISSN - 1472-8206
pISSN - 0767-3981
DOI - 10.1111/j.1472-8206.1992.tb00096.x
Subject(s) - quinpirole , idazoxan , endocrinology , medicine , stimulation , prazosin , chemistry , domperidone , agonist , bradycardia , autonomic nervous system , heart rate , dopamine receptor , dopamine , receptor , antagonist , blood pressure
Summary— The effects of quinpirole, a specific dopamine DA2 receptor agonist, on autonomic nervous control of heart rate, were studied in normotensive pithed rats, by analysing its action on the tachycardia and bradycardia evoked by electrical stimulation of the cardioaccelerator (10 V; 1 ms; 0.5, 1, 3, 6 Hz) and vagus (10 V; 1 ms; 3, 6, 9 Hz) nerves respectively. Quinpirole (10–50–100 μg kg −1 iv) reduced the cardioacceleration elicited by electrical stimulation but not that by noradrenaline (3 μg kg −1 iv). The effect on electrical stimulation was blocked by domperidone (0.5 mg kg −1 iv) but not by SCH 23390 (0.2 mg kg −1 iv) or idazoxan (0.3 mg kg −1 iv). At 1, 5, 10, 30 μg kg −1 iv, quinpirole decreased vagal but not acetylcholine‐induced bradycardia. The effect on electrical stimulation was inhibited by domperidone (0.5 mg kg −1 iv) but not by SCH 23390 (0.2 mg kg −1 iv), prazosin (0.1 mg kg −1 iv) or idazoxan (0.3 mg kg −1 iv). The data point to the presence of presynaptic and/or ganglionic dopamine receptors in the sympathetic and parasympathetic innervation of the rat heart, where stimulation inhibits the release of neuromediators.