Verapamil-induced changes of muscle culture acetylcholinesterase

Publisher Website
Google Scholar
Abstract
Pectoral muscle of 11-day-old normal chick embryos was cultured for 7 days and then treated with verapamil for up to 48 h to test the hypothesis that verapamil affects acetylcholinesterase (ACHE) activity. Cellular ACHE activity increased, activity released into the medium decreased, and net activity decreased with increasing concentrations of verapamil up to 30 μg/mL. Neither protein synthesis nor total cell protein content changed with concentrations of 1–30 μg of verapamil/mL. One hundred micrograms of verapamil per millilitre was toxic to cultures. To determine the effect of verapamil on newly synthesized ACHE, 30 μg of it per millilitre was added to cells treated with diisopropylphosphorofluoridate (DFP). During recovery from DFP, the amount of newly synthesized ACHE released into the medium was increased threefold. Cellular leucine incorporation, total cell protein, and creatine phosphokinase activity were unaffected by the presence of verapamil during cellular recovery from DFP. The results indicate that verapamil has a direct effect on skeletal muscle cells by specifically decreasing net synthesis of ACHE and (or) inhibiting its release from the cell.