The effects of atracurium on neuromuscular transmission in rats
Otagiri, T.
Masui. Japanese Journal of Anesthesiology 33(10): 1122-1129
1984
ISSN/ISBN: 0021-4892 PMID: 6097700 Document Number: 241085
Atracurium was first described as a new non-depolarizing muscle relaxant with intermediate duration of action by Stenlake et al. in 1979. Its desirable characteristic is the lack of cumulative effect because of its rapid metabolism by Hofmann elimination and enzymatic ester hydrolysis. The site of action on neuromuscular transmission of this new drug is not clearly proved. The effect of atracurium was evaluated on miniature end-plate potential (mepp) frequency and amplitude. Using the standard microelectrode recording technique, the isolated rat whole diaphragm was prepared. Atracurium, 10-11 M-10-7 M, produced significant reduction only on mepp amplitudes (P < 0.001); between 10-6 M and 10-5 M, it reduced not only mepp amplitudes but also frequencies significantly. The primary cause of blockade of neuromuscular transmission by atracurium is apparently post-junctional, and besides the primary action, in high concentration, this drug may produce not only post-junctional but also pre-junctional blockade.