In order to investigate the cardiovascular effects of the scorpion(Buthus martensiKarsch)venom(BmKv),the left ventricle of the rats was catheterized via the right carotidartery.The LVP,LVEDP,+dp/dt max,Vmax,HR and BP ...In order to investigate the cardiovascular effects of the scorpion(Buthus martensiKarsch)venom(BmKv),the left ventricle of the rats was catheterized via the right carotidartery.The LVP,LVEDP,+dp/dt max,Vmax,HR and BP were observed.The results showedthat intravenous injection of the BmKv(60μg/kg),in comparison with the control,elicited obvi-ous hypertension and increase of cardiac contractility,both of which lasted for 1h,while theheart rate had no significant change rand that pretreating the rats with alpha-adrenergic blocker,phentolamine,antagonized the hypertensive effects,but did not antagonize the increase of cardiaccontractility.Pretreatment with beta-adrenergic blocker,propranolol,has no influence on the ef-fects of the venom.It is suggested that the hypertensive effects are due to the activation of al-pha-adrenergic receptor,whereas the increase of cardiac contractility may not be resulted fromthe activation of beta-adrenergic receptor.The BmKv treated with dithiothreitol before injectionhad no cardiovascular effects,indicating that the intact disulfide bridges play a decisive role inthe cardiovascular effects of the BmKv.展开更多
文摘In order to investigate the cardiovascular effects of the scorpion(Buthus martensiKarsch)venom(BmKv),the left ventricle of the rats was catheterized via the right carotidartery.The LVP,LVEDP,+dp/dt max,Vmax,HR and BP were observed.The results showedthat intravenous injection of the BmKv(60μg/kg),in comparison with the control,elicited obvi-ous hypertension and increase of cardiac contractility,both of which lasted for 1h,while theheart rate had no significant change rand that pretreating the rats with alpha-adrenergic blocker,phentolamine,antagonized the hypertensive effects,but did not antagonize the increase of cardiaccontractility.Pretreatment with beta-adrenergic blocker,propranolol,has no influence on the ef-fects of the venom.It is suggested that the hypertensive effects are due to the activation of al-pha-adrenergic receptor,whereas the increase of cardiac contractility may not be resulted fromthe activation of beta-adrenergic receptor.The BmKv treated with dithiothreitol before injectionhad no cardiovascular effects,indicating that the intact disulfide bridges play a decisive role inthe cardiovascular effects of the BmKv.