Calcium antagonism in isolated rat uterus by methylmethacrylate.

Methylmethacrylate (MMA) was evaluated for the ability to block actions of calcium in the isolated rat uterine preparation. MMA blocked receptor-mediated contraction and the phasic and tonic portions of the KCl induced contraction of the uterus. The effects of MMA could be antagonized by increasing the concentration of calcium. In the Ca++-free, K-depolarized preparation, MMA produced dose related depression of contraction.