甲基莲心碱对豚鼠心房生理特性及异丙肾上腺素和Ca2+量—效反应的影响

甲基莲心碱1～100μmol/L浓度依赖性地抑制豚鼠左心房收缩性,延长功能性不应期,降低兴奋性;30μmol/L甲基莲心碱能明显提高肾上腺素诱发左心房自律性的阈浓度。对异丙肾上腺素量—效反应的影响,不同于β-受体阻滞剂普萘洛尔,表现为非竞争性拮抗作用,对Ca²⁺量—效反应的影响,与抗钙剂维拉帕米类似,呈竞争性和非竞争性双重拮抗作用。

EFFECTS OF NEFERINE ON PHYSIOLOGIC PROPERTIES AND THE DOSE-EFFECT RESPONSE OF ISOPRENALINE AND Ca2+ IN GUINEA PIG ATRIA

Neferine, an alkaloid extracted from the green seed embryo of Nelumbo nucifera Gaertn, had been shown to have anti-arrhythmic action. Its effects upon the physiologic properties and the dose-effect response of isoprenaline and Ca²⁺ were studied in guinea pig atria.Neferine 30 μmol/L decreased the automaticity-inducing effect of adrenalinene in guinea pig atria. Neferine 1～100 μmol/L, in a concentration-dependent manner, inhibited the force of contraction and excitability, prolonged the functional refractory period on, the left atrium, and reduced the automaticity and contractility of the right atrium.Neferine 30 μmol/L suppressed and shifted the isoprenaline dose-effect curve to the tight non-parallelly, an action different from the action of propranolol. Neferine, as verapamil, showed dualistic action in Ca²⁺-antagonism.