糖尿病大鼠罗库溴铵神经肌肉阻滞作用的药效学

Neuromuscular Pharmacodynamics of Rocuronium in Diabetic Rats

目的观察糖尿病大鼠应用非去极化肌松药罗库溴铵后骨骼肌阻滞效应的药效动力学改变。方法采用链脲佐菌素诱导建立糖尿病大鼠模型。采用随机数字表法将24只雄性SD大鼠分为正常对照组(n=6)、造模2周组(n=6)、造模4周组(n=6)和造模8周组(n=6)。按剂量累计法给予罗库溴铵,采用4个成串刺激(TOF)坐骨神经,在体检测胫前肌颤搐张力变化情况,获得罗库溴铵时效参数[起效时间、TOF的T4/T1比值(TOFr)恢复75%的时间(TOFr75)和恢复90%的时间(TOFr90)],并通过四参数模型拟合剂量效应曲线,计算相应50%有效抑制浓度(IC50)数值。结果糖尿病大鼠罗库溴铵起效时间随糖尿病造模时间增加而逐渐延长,TOFr75和TOFr90时间则逐渐缩短,差异均有统计学意义(P<0.001)。罗库溴铵IC50及95%可信区间在正常、糖尿病造模2周、造模4周和造模8周大鼠分别为0.37(0.35~0.38)mg/kg、0.44(0.43~0.46)mg/kg、0.59(0.57~0.61)mg/kg和0.64(0.61~0.66)mg/kg。与正常大鼠相比,糖尿病各组罗库溴铵IC50均显著升高,而且随糖尿病造模时间延长罗库溴铵IC50逐渐增加,差异均有统计学意义(P<0.001)。结论糖尿病可引起大鼠骨骼肌对罗库溴铵敏感性降低,表现为量效曲线右移,同时罗库溴铵起效时间延长,而肌松恢复时间明显缩短。

Objective To investigate diabetes-mediated changes in the neuromuscular pharmacodynamics of rocuronium in rats. Methods Diabetes mellitus was induced by a single injection of streptozotocin in rats.A total of 24 male SD rats were assigned to four groups using random number table:the normal control group,diabetic 2-week group,diabetic 4-week group,and diabetic 8-week group(6 rats per group).The sciatic nerve was stimulated in a rain-of-four(TOF)pattern,and the twitch tension changes in the tibialis anterior muscle were demonstrated by mechanomyography after intravenous injection of rocuronium in vivo .The time course characteristics of rocuronium,including onset time,and the recovery time from rocuronium injection to TOF ratio 75%(RT75%)and 90%(RT90%),were recorded,and half maximal inhibitory concentration(IC 50 ) values of rocuronium were determined using a four-parameter dose response curve. Results Compared with the normal controls,the diabetic rats had significantly prolonged onset time of rocuronium,while the RT75% and RT90% were decreased at all rocuronium doses( P <0.001).The time course changes became increasingly significant as the duration of diabetes lengthened( P <0.001).The IC 50 and 95% confidence interval values for rocuronium in the normal control group,diabetic 2-week group,diabetic 4-week group,and diabetic 8-week group were 0.37(0.35-0.38)mg/kg,0.44(0.43-0.46)mg/kg,0.59(0.57-0.61)mg/kg,and 0.64(0.61-0.66)mg/kg,respectively.IC 50 values were significantly higher in the diabetic groups vs .normal control( P <0.001)and gradually increased as the duration of diabetes lengthened( P <0.001). Conclusion Diabetes is associated with the rat skeletal muscle hyposensitivity to rocuronium,which is featured by prolonged onset time of rocuronium,decreased RT 75% and RT 90%,and right shift of the cumulative dose-response curve of rocuronium.