4种氨基甙类抗生素对膈肌和四肢肌肉的松弛作用

目的　探讨氨基甙类抗生素—阿贝卡星 (arbekacin ,ABK) ,阿司霉素 (astromicin ,ASTM) ,异帕咪星 (isepamicin ,ISP)和奈替咪星 (netilmicin ,NTL)在家兔的膈肌 ,前胫骨肌和比目鱼肌的神经肌肉抑制作用。方法　将 2 4只家兔平均分成 4组 ,戊巴比妥静脉麻醉下分别游离膈神经 -膈肌 ,胫神经 -前胫骨肌和腓总神经 -比目鱼肌 ,然后在膈肌表面和肢体肌远端肌腱固定连接肌张力换能测定装置以及在上述神经固定神经刺激电极 ,给予频率为 0 1Hz ,持续 0 1ms ,间隔 10s的超强电刺激。采用累积剂量给药法分别静脉注射以上被验 4种抗生素 ,记录刺激神经所诱发的肌肉等张颤搐强度 ,评价抗生素在 3种肌群不同神经肌肉抑制作用。结果　 4种抗生素在以上 3种骨骼肌肌群均表现不同程度的抑制作用 ,在初期剂量给药时 ,膈肌对药物的敏感性较明显 ,比目鱼肌表现相对最弱。抗生素作用于这 3种肌群的ED50 值大小顺序为比目鱼肌 >前胫骨肌 >膈肌和ED95值大小顺序为比目鱼肌 >膈肌 >前胫骨肌。抗生素在前胫骨肌和比目鱼肌的ED50 值约分别为膈肌的 1 5和 2 7倍。 4种抗生素间神经肌肉抑制作用强度顺序为NTL >ABK >ASTM >ISP。这些抗生素引起的神经肌肉抑制作用可以被新斯的明和钙剂所拮抗。结论　 4种氨基甙类抗生素在膈肌相

The Neuromuscular Blocking Effects of Aminoglycoside Antibiotics on Diaphragm and Limb Muscles

Objective To investigate the neuromuscular blocking effects of the aminoglycoside antibiotics arbekacin(ABK), astromicin(ASTM), isepamicin(ISP) and netilmicin(NTL) on diaphragm muscle, antero-tibialis and soleus in rabbits. Methods Twenty-four rabbits were divided into 4 groups, each group containing 6 animal. The rabbits were anesthetized with sodium pentobarbital intravenously. Then the left phrenic nerve-diaphragm, tibial nerve-tibialis anterior and common peroneal nerve-soleus were gently freed. The freed muscles were connected with muscle force displacement transducers, and were directly stimulated by electrodes with supramaximal square waves of 0 1ms duration at a frequency of 0 1Hz in every 10s. Arbekacin, astromicin, isepamicin and netilmicin were injected intravenously into the animals respectively, then the neuromuscular blocking effect of these antibiotics were assessed, and the isometric force of twitch tention caused by direct single stimulation on the nerves was recorded. Results The different potencies of neuromuscular blocking of 4 antibiotics were found between diaphragm and limb muscles, which were the strongest in the diaphragm muscle and the weakest in the soleus in the initial period of administration of antibiotics. The rank orders of the ED 50 and ED 95 values for the different muscles were soleus >antero-tibialis>diaphragm muscle and soleus >diaphragm muscle>antero-tibialis, respectively. The ED 50 values of 4 antibiotics in the antero-tibialis and soleus were approximately 1 5 and 2 7 times greater than those in the diaphragm muscle. The rank orders of the neuromuscular blocking potency of these antibiotics were NTL>ABK>ASTM>ISE. Conclusion The neuromuscular blocking effects of 4 antibiotics were significantly greater in diaphragm muscle than those in limb muscles.