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Vasoconstrictor and cardiotonic actions of Haloxylon recurvum extract
Author(s) -
Gilani AnwarUl Hassan,
Shaheen Farhana
Publication year - 1994
Publication title -
phytotherapy research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.019
H-Index - 129
eISSN - 1099-1573
pISSN - 0951-418X
DOI - 10.1002/ptr.2650080215
Subject(s) - phentolamine , chronotropic , propranolol , inotrope , norepinephrine , stimulation , pharmacology , chemistry , receptor , blood pressure , biology , endocrinology , heart rate , biochemistry , dopamine
Intravenous administration of an ethanolic extract of Haloxylon recurvum (30–300 μg/kg) caused a rise in arterial blood pressure in normotensive anaesthetized rats. Pretreatment of animals with phentolamine (1 mg/kg) abolished the vasoconstrictor response of the plant extract in a way similar to that of norepinephrine (NE). In an isolated rabbit aorta preparation, both plant extract and NE produced contractile responses which were blocked by phentolamine (0.3 μg/mL). In isolated guinea‐pig atria, the plant extract caused positive inotropic and chronotropic responses similar to that of NE and was blocked by propranolol (0.3 μg/mL). These results suggest that vasoconstrictor and cardiac stimulatory effects of the plant extract are mediated through mechanisms similar to those of NE (stimulation of α‐adrenergic receptors in the blood vessels and cardiac β‐receptors respectively) and hence this plant contains sympathomimetic constituent(s).