EFFECTS OF LIENSININE ON HAEMODYNAMICS IN RATS AND THE PHYSIOLOGIC PROPERTIES OF ISOLATED RABBIT ATRIA

Liensinine(Lien), an alkaloid extracted from the green seed embryo of Nelumbo nucifera Gaertn, has been shown to have anti-arrhythmic action, its mechanism may be related toblockade of Ca²⁺,Na⁺ influx. Lien 3 mg/kg iv may temporarily inhibit all parameters of haemo-dynamics in anesthetized or pithed rats. The inhibitory effects on LVP, +dp/dt_max, and SAP in anes-thetized rats are slightly stronger than those of quinidine(Oui) 3 mg/kg. Lien 1～30 mg/kg dose-de-pendently produced these actions. Lien and Qui 12 mg/kg lowered LVP, +dp/dt_max, and SAP by33%, 37%, 29% and 9%, 12%, 9% respectively. While both of them inhibited the other param-eters of haemodynamics with nearly equal degrees. The degrees of inhibitory effect of Lien 12 mg/kgon all haemodynamic parameters nearly corresponded to these of verapamil 1 mg/kg. Lien 1～100μmol/L reduced the contractile force of isolated left atria and the spontaneously beating rate of isolatedright atria of rabbits in concentration-dependent manner. Thes esults indicate that the properties of the effect of Lien on haemodynamics may be similar to those of verapamil and different from those ofQui.