Azathioprine: effects on neuromuscular transmission.

  • 1 December 1976
    • journal article
    • Vol. 45  (6) , 604-9
Abstract
The neuromuscular effects of azathioprine were examined in the in-vivo cat soleus muscle preparation. In concentrations ranging from 10 to 1,000 mug/kg, administered intra-arterially, the agent caused motor axons to fire repetitively and produced a dose-related increase in the force of contraction. The drug reversed neuromuscular blockage produced by d-tubocurarine and potentiated the neuromuscular blockade produced by succinylcholine. The effects of theophylline, a phosphodiesterase inhibitor, on neuromuscular transmission were identical to those produced by azathioprine. Using an in-vitro assay preparation, azathioprine was found to produce 50 per cent inhibition (IC50) of phosphodiesterase at a concentration of 2 X 10(-5) M. In the same preparation, theophylline had an IC50 of 1 X 10(-4) M. Neither agent in concentrations to 10(-2) M affected cholinesterase activity measured in vitro. It is concluded that the effects of azathioprine on neuromuscular transmission are due to inhibition of phosphodiesterase in the motor nerve terminal.

This publication has 0 references indexed in Scilit: