The stabilization of vascular smooth muscle by procaine.

Procaine acts on the cell membrane as a depolarizing agent. It inhibits K-conductance; as a consequence, the membrane is depolarized and the spike potential is readily generated by outward current pulses. This inhibition of the K-conductance of membrane induced by procaine is discussed in relation to the K channel classified by the patch clamp procedure. The authors' observations indicate that procaine acts as a stimulant rather than as a stabilizer of the membrane. Furthermore, procaine inhibits the release of Ca from the store site, with no effect on the contractile protein. This local anaesthetic agent acts not only on the surface membrane but also on the internal membrane, the sarcoplasmic reticulum. Procaine reduces mechanical activity and stabilization of vascular smooth muscles occurs.