Effects of the water extract of Chrysanthemum indicum Linn. on coronary and systemic hemodynamics in the dog.

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.