Aqueous extract of Zanthoxylum schinifolium elicits contractile and secretory responses via beta1-adrenoceptor activation in beating rabbit atria.
OBJECTIVE
Although Zanthoxylum schinifolium has long been used in the traditional oriental medicine, cardiac effects have not well been documented. The aim of the present study was to investigate the effects of aqueous extract of leaves and stems from Zanthoxylum schinifolium (AZS) on inotropic effect and atrial natriuretic peptide (ANP) secretion.


METHODS
The AZS-induced changes in atrial dynamics, cAMP efflux and atrial ANP secretion were determined in isolated perfused beating rabbit atria.


RESULTS
AZS increased atrial pulse pressure, stroke volume, and cAMP efflux concomitantly with inhibition of ANP secretion in a concentration-dependent manner. The AZS-induced increases in atrial dynamics and cAMP efflux, and decrease in ANP secretion were attenuated by pretreatment with propranolol and CGP 20712 but not ICI 118,551. Also, the AZS-induced changes in atrial dynamics and ANP secretion were attenuated by diltiazem and KT 5720. Diltiazem and KT 5720 had not significant effect on the AZS-induced increase in cAMP efflux.


CONCLUSIONS
These results suggest that AZS elicits a positive inotropic effect and decrease in ANP secretion via beta(1)-adrenoceptor-cAMP-Ca(2+) signaling in beating rabbit atria.
Cui
Hao Zhen
HZ
Professional Graduate School of Oriental Medicine, Wonkwang University, Iksan, Jeonbuk, 570-749, Republic of Korea.
Choi
Hye Ran
HR
Choi
Deok Ho
DH
Cho
Kyung Woo
KW
Kang
Dae Gill
DG
Lee
Ho Sub
HS
D000818:Animals; D009320:Atrial Natriuretic Factor / Q000378:metabolism; D001794:Blood Pressure / Q000187:drug effects; D002227:Carbazoles / Q000494:pharmacology; D002316:Cardiotonic Agents / Q000494:pharmacology*; D002317:Cardiovascular Agents / Q000494:pharmacology; D000242:Cyclic AMP / Q000378:metabolism*; D004110:Diltiazem / Q000494:pharmacology; D006325:Heart Atria / Q000187:drug effects* / Q000378:metabolism; D006439:Hemodynamics / Q000187:drug effects*; D007093:Imidazoles / Q000494:pharmacology; D010936:Plant Extracts / Q000494:pharmacology*; D018515:Plant Leaves; D018547:Plant Stems; D011412:Propanolamines / Q000494:pharmacology; D011433:Propranolol / Q000494:pharmacology; D011758:Pyrroles / Q000494:pharmacology; D011817:Rabbits; D018342:Receptors, Adrenergic, beta-1 / Q000378:metabolism*; D013318:Stroke Volume / Q000187:drug effects; D032106:Zanthoxylum
D002227:Carbazoles; D002316:Cardiotonic Agents; D002317:Cardiovascular Agents; D007093:Imidazoles; D010936:Plant Extracts; D011412:Propanolamines; D011758:Pyrroles; D018342:Receptors, Adrenergic, beta-1; C026777:ICI 118551; C057416:KT 5720; D009320:Atrial Natriuretic Factor; D011433:Propranolol; C049763:CGP 20712A; D000242:Cyclic AMP; D004110:Diltiazem