P物质对去甲肾上腺素诱发大鼠离体心脏功能变化的影响

目的 探讨P物质(SP)对去甲肾上腺素(NE)诱发大鼠离体心脏功能变化的影响.方法 健康成年雄性SD大鼠54只,体重250～280 g,随机分为9组:对照组(C组,n=6);10-6mol/L SP组(SP1组,n=6);10-7mol/L SP组(SB组,n=6);10-8mol/L SP组(SP3组,n=6);10-5mol/L NE组(NE1组,n=6);10-6mol/L NE组(NE2组,n=6);10-7mol/L NE组(NE3组,n=6);10-8mol/L SP+10-5mol/L NE组(SN组,n=6);10-7 mol/L NK-I受体拮抗剂+10-8 mol/L SP+10-5mol/L NE组(DSN组,n=6).分离大鼠心脏,采用Langendorff装置灌流离体心脏,记录给药后10 min内的左室收缩压(LVSP)、左室舒张末期压(LVEDP)、左室发展压(LVDP)和心率(HR),计算各指标变化率.结果 与C组比较,NE1组、NE2组和NE3组LVDP、LVSP和HR的变化率均升高,NE1组升高最明显,NE1组LVEDP变化率明显降低(P<0.05);与NE1组比较,SN组LVDP和LVSP变化率升高、HR变化率降低(P<0.05);与SN组比较,DSN组LCDP和LVSP的变化率降低(P<0.05);与NE1组比较,DSN组HR变化率降低(P<0.05).结论 10-7～10-5mol/L NE对心脏可产生明显正性变时变力作用,10-8～10-6mol/L SP对心脏无直接作用,但可增强NE的正性变力作用,抑制NE的正性变时作用;其机制可能与NK-1受体激活有关.

Effects of substance P on norepinephrine-induced changes in cardiac function of isolated rat hearts

Objective To investigate the effects of substance P (SP) on norepinephrine (NE)-induced changes in cardiac function of isolated rat hearts. Methods Fifty-four healthy male SD rats weighing 250-280 g were randomly divided into 9 groups ( n = 6 each) : group Ⅰ control (C) ; group Ⅱ , Ⅲ , Ⅳ received SP 10-6 , 10-7and 10-8 mol/L respectively (SP1 , SP2, SP3 ) ; group Ⅴ, Ⅵ, Ⅶ received NE 10-5, 10-6 and 10-7 mol/L respectively (NE1 ,NF2 ,NE3); group Ⅷ received SP 10-8mol/L + NE 10-5 mol/L (SN) and group Ⅸ received NK-1 (SP receptor antagonist) 10-7 mol/L + SP 10-8 mol/L + NE 10-5 mol/L (DSN).Tbe animals were anesthetized with intraperitoneal 25 % urethane 1.4-1.8 ml. Their hearts were excised and retrogredely perfused in a Langendorff apparatus. The isolated hearts received the drugs via the perfusion system after 10 min stabilization. Left ventricular systolic pressure (LVSP), left ventricular end-diastolic pressure (LVEDP), left ventriculur developed pressure (LVDP) and HR were monitored and recorded before and every minute after drug administration for 10 min. The change rate of each parameter was calculated. Results The LVDP, LVSP and HR were significantly increased while LVEDP was significantly decreased after NE administration in group NE1, NE2 and NF3 as compared with group C, especially in group NE1. There was no significant difference in all parameters of cardiac function between group C and the 3 SP groups. LVDP and LVSP were significantly higher, while HR was significantly lower after drug administration in group SN ( group Ⅷ ) than in group NE1 . The LVDP and LVSP were significantly lower after drug administration in group DSN ( Ⅸ ) than in group SN ( Ⅷ ), but there was no significant difference in HR between the 2 groups. Conclusions NE 10-7- 10-5 mol/L can exert positive inotropic and chronotropic effects on normal isolated rat hearts. SP 10-8- 10-6 mol/L have no direct effect on cardiac function, but it can enhance NE-induced positive inotropic effect and inhibit NE-induced positive chronotropic effect through NK-1 receptor.