摘要目的 采用离体实验评价辣椒素对糖尿病大鼠心脏功能障碍的影响.方法 健康雄性SD大鼠,体重240~260 g,腹腔注射链脲佐菌素50 mg∕kg制备1型糖尿病模型.造模成功后8周,取18只糖尿病大鼠,采用随机数字表法分为3组(n=6):糖尿病组(DM组)、辣椒素组(CAP组)和辣椒素+辣椒平组(CPZ组).另取8只血糖正常的大鼠作为对照组(C组).深麻醉状态下取心脏,连接于Langendorff离体心脏灌流装置,采用氧合K-H液(37 ℃恒温)逆行灌注心脏.心脏功能稳定10 min时,C组和DM组继续灌注K-H液30 min;CAP组继续灌注K-H液20 min,然后采用微量输注泵经主动脉套管侧支以0.5 ml∕min的速率输注辣椒素(1.4×10-9g∕L)10 min;CPZ组继续灌注K-H液10 min,然后采用微量输注泵先经主动脉套管侧支以0.5 ml∕min 的速率输注辣椒素受体—瞬时感受器电位香草酸受体1拮抗剂辣椒平(1.4×10-7g∕L)10 min,再以0.5 ml∕min 的速率输注辣椒素(1.4× 10-9g∕L)10 min.于继续灌注10、20和30 min(T1-3)时,记录左心室收缩压(LVSP)、左心室发展压(LVDP)、左心室舒张末压(LVEDP)、HR、左心室收缩最大变化速率(+dp∕dtmax)和左心室舒张最大变化速率(-dp∕dtmax).结果 4组间各时点LVEDP、+dp∕dtmax和-dp∕dtmax比较差异无统计学意义(P>0.05);与C组比较,DM组和CPZ组T1-3时、CAP组T1-2时LVSP和LVDP降低,DM组、CPZ组和CAP组T1-3时HR降低(P<0.05);与DM组比较,CAP组T3时LVSP和LVDP升高(P<0.05),CPZ组各时点LVSP和LVDP差异无统计学意义(P>0.05);与CAP组比较,CPZ组T3时LVSP和LVDP降低(P<0.05).结论 辣椒素可减轻糖尿病大鼠离体心脏障碍功能,其机制与激活瞬时感受器电位香草酸受体1有关.

abstractsObjective To evaluate the effect of capsaicin on cardiac dysfunction in diabetic rats u-sing an in vitro experiment. Methods Healthy male Sprague-Dawley rats, weighing 240-260 g, in which type 1 diabetes mellitus was induced by intraperitoneal streptozotocin 50 mg∕kg, were studied. Eighteen di-abetic rats were selected at 8 weeks after successful establishment of the model and divided into 3 groups (n=6 each)using a random number table: diabetes mellitus group(DM group), capsaicin group(CAP group)and capsaicin plus capsazepine group(CPZ group). Another 8 rats with normal blood glucose served as control group(C group). Rat hearts were quickly removed under deep anesthesia and retrogradely perfused with an oxygen-saturated K-H solution(at 37℃)using a Langendorff apparatus. Cardiac function was maintained stable for 10 min. The hearts were continuously perfused with K-H solution for 30 min in C and DM groups. The hearts were perfused with K-H solution for 20 min, and capsaicin(1.4×10-9g∕L)was then infused for 10 min via the branch of aortic cannula using micro pump in CAP group. The hearts were perfused with K-H solution for 10 min, and capsaicin receptor-transient receptor potential vanilloid type 1 antagonist capsazepine(1.4×10-7g∕L)was then infused for 10 min followed by infusion of capsaicin(1.4× 10-9g∕L)at 0.5 ml∕min for 10 min via the branch of aortic cannula using a micro-pump in CPZ group. Left ventricular systolic pressure(LVSP), left ventricular developed pressure(LVDP), left ventricular end-di-astolic pressure(LVEDP), heart rate, the maximum rate of increase or decrease in left ventricular pres-sure(±dp∕dtmax)were recorded at 10, 20 and 30 min of continuous infusion(T1-3). Results There was no significant difference in LVEDP and ± dp∕dtmaxat each time point among the four groups(P>0.05). Compared with C group, LVSP and LVDP were significantly decreased at T1-3in DM and CPZ groups and at T1-2in CAP group, and heart rate was significantly decreased at T1-3in DM, CPZ and CAP groups(P<0.05). Compared with DM group, LVSP and LVDP were significantly increased at T3in CAP group(P<0.05), and no significant change was found in LVSP or LVDP in CPZ group(P>0.05). LVSP and LVDP were significantly lower at T3in CPZ group than in CAP group(P<0.05). Conclusion Capsaicin can mitigate cardiac dysfunction in diabetic rats, and the mechanism is related to activating transient receptor potential vanilloid type 1.