Effects Of Quinghaosu Antimalaria Artemether On Blood Pressure, Heart Rate And Baroflex Sensitivity In Normotensive Rats
AbstractThe effects of Chronic administration of the new antimalaria drug artemether on cardiovascular function were investigated in albino Sprague-Dawley rats. One group of rats received 3.2mg/kg artemether (Therapeutic dose) and a second group received 18mg/kg of artemether while the control group received vehicle (refined corn oil) for 28 days. The animals were anaesthetized thereafter and cannulated for recording of blood pressure and testing of cardiovascular reflexes.
Results from the study showed that artemether had little or no effect on mean arterial pressure (MAP) both at the therapeutic and high doses compared to the controls (90.37+4.3 and 97.1+2.7mmHg respectively cf 88.35+2.6mmHg, NS). Heart rate (HR) did not change significantly in the artemether treated rats. However during bilateral carotid occlusion (BC)) the magnitude of the change in blood pressure (MAP) and heart rate (HR) were reduced in the group that received 18mg/kg artemether (41.55+2.1mmHg; p<0.05). The maximum change in heart rate (MAX,HR) was not different between the control rats and rats treated with artemether at 3.2mg/kg (18.1+1.6 beats/min cf 18.6+1.2 beats/min) while in rats treated withartemether 18mg/kg artemether MAX, HR was reduced to 9.77+0.77 beats/min (p<0.05).
Both therapeutic and high doses of artemether reduced the index of baroreflex sensitivity in this study. The results from this study suggest that whilst artemether may not have significant effect on resting cardiovascular function, it may interfere with ability of the cardiovascular system to respond to the challenges.
Key Words: Arthemether, Blood Pressure, Heart Rate, Baroreflex sensitivity
[J. of Med. & Medical Sci. Vol.1(1) 1999: 50-54]