Cardiovascular pharmacology of aqueous extract of the leaves of Bridelia atroviridis Muell. Arg. (Euphorbiaceae) in the rat.
Lyophilised decoction (10%) of the leaves of Bridelia atroviridis Muell. Arg. (Euphorbiaceae) was studied in the rat cardiovascular system. In vivo, the extract (15 and 30 mg/kg) caused a decrease of arterial pressure and a decrease of heart rate in an anaesthetized rat (ethylcarbamate 1.2 g/kg). If administrations of Bridelia were repeated (three times) a tachyphylaxie phenomena was observed. After administrations of adrenaline, noradrenaline, acethylcholine and isoprenaline the extract had no effect on the action of these neuromediators on blood pressure. In vitro the extract induced dose-dependent negative inotropic and chronotropic effects in isolated rat heart. It was ineffective in rat aorta preparations. Bridelia seemed to have a direct effect on rat heart. Hypotension is not due to an action on the vessels. The extract did not appear to interact with adrenergic nor cholinergic receptors. However, the extract was able to potentiate barium chloride induced contractions of rat aorta preparations. The extract might act through potential dependent calcium channels.
Corallo
A
A
Laboratory of Physiology-Pharmacology, Faculty of Pharmacy, University of Abidijan, Côte d'Ivoire.
Foungbé
S
S
Davy
M
M
Cohen
Y
Y
D000818:Animals; D001011:Aorta / Q000187:drug effects / Q000378:metabolism; D001794:Blood Pressure / Q000187:drug effects*; D015220:Calcium Channels / Q000187:drug effects; D002316:Cardiotonic Agents / Q000008:administration & dosage / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D004347:Drug Interactions; D006321:Heart / Q000187:drug effects*; D006339:Heart Rate / Q000187:drug effects*; D007022:Hypotension / Q000139:chemically induced; D066298:In Vitro Techniques; D008297:Male; D008519:Medicine, Traditional; D009119:Muscle Contraction / Q000187:drug effects; D009131:Muscle, Smooth, Vascular / Q000187:drug effects; D009200:Myocardial Contraction / Q000187:drug effects*; D018377:Neurotransmitter Agents / Q000037:antagonists & inhibitors*; D010936:Plant Extracts / Q000008:administration & dosage / Q000494:pharmacology* / Q000633:toxicity; D018515:Plant Leaves; D051381:Rats; D017207:Rats, Sprague-Dawley; D011941:Receptors, Adrenergic / Q000187:drug effects*; D011950:Receptors, Cholinergic / Q000187:drug effects*; D013618:Tachyphylaxis
D015220:Calcium Channels; D002316:Cardiotonic Agents; D018377:Neurotransmitter Agents; D010936:Plant Extracts; D011941:Receptors, Adrenergic; D011950:Receptors, Cholinergic