Effects of the water extract of Chrysanthemum indicum Linn. on coronary and systemic hemodynamics in the dog.
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Abstrakcyjny
To clarify the pharmacological profile and the mechanism of action of the water extract of flower of Chrysanthemum indicum Linn. (CIL), a crude drug, the effects of CIL on coronary and systemic hemodynamics were examined in anesthetized open-chest dogs, and the coronary relaxing action of CIL was tested on isolated dog coronary arterial strips. Intravenous administration of CIL 5-20 mg/kg produced a decrease in aortic blood pressure and increases in coronary blood flow, left ventricular dP/dt and heart rate in a dose-dependent manner. Renal blood flow initially decreased and then increased to the values above the preinjection level. These changes by every dose of CIL returned to the preadministration level until 5 min. Dipyridamole (0.1 mg/kg i.v.) potentiated an increase in coronary blood flow of CIL and aminophylline (1.0 mg/kg i.v.) attenuated this response. Intravenous administration of adenosine 5-50 micrograms/kg produced effects similar to those of CIL. The doses of CIL and adenosine which produced a two-fold increase in coronary blood flow were 13.8 mg/kg and 29.5 micrograms/kg, respectively. In 30 mM potassium-induced contracture of dog coronary arterial strips, there was no difference in the relaxant response to CIL between large coronary arteries and medium-size coronary arteries. Adenosine tended to produce a larger relaxation in medium-size coronary arteries than in large coronary arteries. The results indicate that CIL has a coronary vasodilating action and a renal vasoconstricting action in the open-chest dog and that the pharmacological profile of CIL is in part similar to that of adenosine.