The effect of baclofen on the cardiovascular system of the rat.
1 The cardiovascular responses to baclofen were investigated in anaesthetized rats. 2 Low doses of baclofen (less than 5 X 10(-8) mol), given intravenously, produced a transient fall in blood pressure and heart rate. Higher doses (greater than 5 X 10(-7) mol) produced a marked and prolonged increase in blood pressure accompanied by a rise in heart rate and cutaneous arterial dilatation. 3 The pressor and heart rate responses exhibited tachyphylaxis, and were abolished by hexamethonium, cervical cord section, reserpine-treatment and by a combination of alpha- and beta-adrenoceptor antagonists. 4 It is concluded that the increases in blood pressure and heart rate produced by high doses of baclofen are of central sympathetic origin.
D000317:Adrenergic alpha-Antagonists / Q000494:pharmacology; D000319:Adrenergic beta-Antagonists / Q000494:pharmacology; D000818:Animals; D001158:Arteries / Q000187:drug effects; D001418:Baclofen / Q000494:pharmacology*; D001794:Blood Pressure / Q000187:drug effects*; D006339:Heart Rate / Q000187:drug effects*; D006584:Hexamethonium Compounds / Q000494:pharmacology; D008297:Male; D051381:Rats; D012110:Reserpine / Q000494:pharmacology; D014664:Vasodilation / Q000187:drug effects; D005680:gamma-Aminobutyric Acid / Q000494:pharmacology
D000317:Adrenergic alpha-Antagonists; D000319:Adrenergic beta-Antagonists; D006584:Hexamethonium Compounds; D005680:gamma-Aminobutyric Acid; D012110:Reserpine; D001418:Baclofen