丙泊酚静脉注射对大鼠心室功能及心肌β肾上腺素受体的影响

目的研究丙泊酚静脉注射对大鼠心室功能及心肌β肾上腺素受体密度及亲和力的影响。方法24只清洁级雄性Wistar大鼠随机分为3组,每组8只:对照组、丙泊酚5 mg·kg~(-1)组及丙泊酚10 mg·kg~(-1)组。记录丙泊酚给药前及给药后30 min内所有动物的心率(HR)、左室收缩压(LVSP)及左室内压力变化最大速率(+dp/dt_(max)、-dp/dt_(max)),并采用放免法测定给药后30 min时心肌β肾上腺素受体密度(B_(max))及亲和力(K_d)。结果(1)HR、LVSP、+dp/df_(max)及-dP/dt_(max)分别在丙泊酚5 mg·kg~(-1)静脉给药后9、5、30及9 min内明显低于给药前值;并在给药后9、7、7及9 min内分别明显低于对照组(P<0.05或0.01)。HR、LVSP、+dp/dt_(max)及-dp/df_(max)分别在丙泊酚10 mg·kg~(-1)静脉给药后25、5、30及8 min内明显低于给药前值;并在给药后8、7、7及8 min内分别明显低于对照组(P<0.05或0.01)。丙泊酚2组间比较无明显差异(P>0.05)。(2)丙泊酚5 mg·kg~(-1)组及10 mg·kg~(-1)组B_(max)明显高于对照组(P<0.01);丙泊酚10 mg·kg~(-1)组K_d值明显高于对照组及丙泊酚5 mg·kg~(-1)组(P<0.05);其余各组间比较无明显差异(P>0.05)。结论丙泊酚可引起给药后30 min内心室功能抑制,5 mg·kg~(-1)及10 mg·kg~(-1)上调给药后30 min心肌β肾上腺素受体密度。

Influences of propofol injected intravenously on ventricular function and beta adrenergic receptor in myocardium in rats

AIM To investigate the influences of propofol injected intravenously on ventricular function and the beta adrenergic receptor density(B_(max))and affinity(K_d)in myocardium in rats.METHODS Twenty- four male Wistar rats were randomly divided into 3 groups with 8 in each:control group,propofol 5 mg·kg~(-1) group and propofol 10 mg·kg~(-1)group.Propofol were injected intravenously within 15 s.The heart rate(HR), the left ventricle pressure(LVSP),and the maximal/minimum rate of LVSP(+dp/dt-(max)-dp/dt_(max)before propofol injected and 30 min after propofol injected were measured.All the rats were killed for determining the B_(max)and K_d 30 min after propofol injected through radioligand binding assays RESULTS(1)Propofol 5 mg·kg~(-1)induced the decrease of HR in 9 min,LVSP in 5 min,+dp/dt_(max)in 30 min,and -dp/dt_(max)in 9 min compared to the value before injected,and the decrease of HR in 9 min,LVSP in 7 min,+dp/dt_(max)in 7 min, and -dp/dt_(mxa)in 9 min compared with control group(P<0.05 or P<0.01).Propofol 10 mg.kg~(-1)induced the decrease of HR in 25 min,LVSP in 5 min,+dp/dt_(mxa)in 30 min,and-dp/dt_(mxa)in 8 min compared to the value before injected,and the decrease of HR in 8 min,LVSP in 7 min,+dp/dt_(mxa)in 7 min,and-dp/dt_(mxa)in 8 min compared with control group(P<0.05 or P<0.01).There was no significant difference between propofol 5 mg·kg~(-1)group and propofol 10 mg·kg~(-1)group(P>0.05).(2)B_(mxa)in propofol 5 mg·kg~(-1)and 10 mg'kg~(-1)groups and K_d value in propofol 10 mg.kg~(-1)group were increased significantly compared with that in control group(P<0.05 or P<0.01),and K_d value in propofol 10 mg·kg~(-1)group was higher than that in propofol 5 mg'kg~(-1)group (P<0.05).CONCLUSION Propofol 5 mg·kg~(-1)and 10 mg·kg~(-1)can inhibit ventricular function,and increase the B_(mxa)of myocardium in 30 min after injected.