[Cardiovascular protective effects and NO-mediated cerebrovasorelaxant effects of extract of ginkgo biloba leaves].
OBJECTIVE
To examine the anti-free radical related cardiovascular protective effects and NO-mediated cerebrovasorelaxant effects of extract of the leaves of Ginkgo biloba(EGb) in isolated preparations.


METHODS
Experiments on the anti-free radical related cardiovascular protective effects were performed in rabbit Langendorff heart and isolated aortic rings damaged by diphenyl-picryl hydyazyl(DPPH). Protective effects of EGb were determined by comparing the results of EGb pretreated group with the DPPH-injured controls. Cerebrovasorelaxant effects of EGb were examined in ring preparations of isolated porcine basilar artery in vitro using tissue bath techniques.


RESULTS
EGb protected the isolated rabbit heart from the DPPH-injury to the cardiac contractility and the aortic endothelium from DPPH-attenuated ACh-induced relaxation. EGb concentrationde dependently relaxed the basilar artery and this effect was more significant in endothelium intact rings than those endothelium denuded rings. EGb enhanced the TNS-induced relaxation in basilar artery and this effect was abolished by pretreatment of N-nitro-L-arginine or tetrodotoxin.


CONCLUSIONS
EGb exerts cardiovascular protection against DPPH-impaired cardiac contraction in rabbit isolated heart and endothelium-dependent relaxation in the aortic ring of rabbit in vitro. EGb relaxes porcine basilar artery and enhances the TNS-induced relaxation via a NO pathway.
Chen
X
X
Department of Pharmacology, Hunan Medical University, Changsha.
Liu
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L
Li
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Z
D000818:Animals; D001488:Basilar Artery; D015764:Bepridil / Q000031:analogs & derivatives; D001713:Biphenyl Compounds; D002319:Cardiovascular System / Q000187:drug effects*; D004365:Drugs, Chinese Herbal / Q000302:isolation & purification / Q000494:pharmacology; D005609:Free Radicals; D020441:Ginkgo biloba / Q000737:chemistry*; D066298:In Vitro Techniques; D051379:Mice; D009569:Nitric Oxide / Q000378:metabolism*; D010851:Picrates; D018515:Plant Leaves / Q000737:chemistry; D010946:Plants, Medicinal; D011817:Rabbits; D013552:Swine; D014665:Vasodilator Agents / Q000494:pharmacology*
D001713:Biphenyl Compounds; D004365:Drugs, Chinese Herbal; D005609:Free Radicals; D010851:Picrates; D014665:Vasodilator Agents; D009569:Nitric Oxide; D015764:Bepridil; C004931:1,1-diphenyl-2-picrylhydrazyl