NEUROMUSCULAR BLOCKING EFFECT OF THIAMPHENICOL ON FROG RECTUS-ABDOMINIS MUSCLE

1. In the present study, thiamphenicol caused a significant fall in AC h-induced frog rectus abdominis muscle contraction peaks and significa nt rightward shifts of the contractile response curves in a dose-depen dent manner. 2. In addition, the maximal ACh response of muscle could not be obtained in presence of thiamphenicol. On the other hand, thiam phenicol did not alter KCl-induced contractions of the muscle at the s ame concentrations. 3. In contrast chloramphenicol did not cause any s ignificant change in ACh-induced contraction peaks. 4. These results h ave suggested that thiamphenicol may have a neuromuscular blocking eff ect on frog rectus abdominis muscle.