Artesunate causes relaxation of rat aortic rings and reduces the contractile response to noradrenaline.
OBJECTIVE
To study if the present widely used artemisin derived anti-malaria drugs have vascular effects.


METHODS
Aortic rings were obtained from adult male Sprague-Dawley rats. The rings were mounted in an organ bath and tension recorded using isometric force transducers. After pre-contraction with noradrenaline, cumulative doses of artesunate were added to the bath containing the rings. The effects of nitric oxide inhibition with L-NAME, on the responses to artesunate were also assessed. Lastly the effects on the contractile responses of the rings to noradrenaline (NA) were determined before and after incubation in artesunate.


RESULTS
Cumulative addition of artesunate from 6 x 10(-4) to 6 x 10(-1) mg/ml resulted in relaxation of pre-contracted aortic rings. L-NAME significantly reduced the relaxation response to artesunate (P < 0.05). Vascular contraction response to NA was significantly reduced (P < 0.01) following the addition of artesunate.


CONCLUSIONS
Artesunate causes relaxation of precontracted rat aortic rings which is partly mediated by Nitric Oxide (EDRF). It also reduces the contractile responses of the rings to noradrenaline.
Sofola
O A
OA
Department of Physiology, College of Medicine & Faculty of Pharmacy, University of Lagos.
Raji
I
I
Ladipo
C
C
Coker
H A B
HA
D000704:Analysis of Variance; D000818:Animals; D000962:Antimalarials / Q000494:pharmacology*; D001011:Aorta / Q000187:drug effects*; D037621:Artemisinins / Q000494:pharmacology*; D000077332:Artesunate; D045462:Endothelium-Dependent Relaxing Factors / Q000494:pharmacology*; D004791:Enzyme Inhibitors / Q000494:pharmacology; D008297:Male; D009200:Myocardial Contraction / Q000187:drug effects*; D019331:NG-Nitroarginine Methyl Ester / Q000494:pharmacology*; D009569:Nitric Oxide / Q000037:antagonists & inhibitors*; D009638:Norepinephrine / Q000494:pharmacology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D014662:Vasoconstrictor Agents / Q000494:pharmacology
D000962:Antimalarials; D037621:Artemisinins; D045462:Endothelium-Dependent Relaxing Factors; D004791:Enzyme Inhibitors; D014662:Vasoconstrictor Agents; D009569:Nitric Oxide; D000077332:Artesunate; D019331:NG-Nitroarginine Methyl Ester; D009638:Norepinephrine