Local Anesthetic Activity of 1-(Morpholino or Piperidino)-2-Propanol Derivatives

Abstract

The local anesthetic activities of 1-(morpholino or piperidino)-2-propanol derivatives were investigated in the frog, rabbit, guinea pig and cat. These activities were observed with nerve trunk anesthesia, rabbit''s corneal anesthesia and intradermal injection anesthesia. Among these propanol derivatives, those which possess thioether-type S were the most active and the effective potency was enhanced by increasing the dissociation constant (pKa) value in a series of the compounds. Effects on cat spinal reflex were also observed. These propanol derivatives revealed no selective depression of presynaptic depression or depression of the potential of monosynaptic reflex (MSR) and polysynaptic reflex (PSR). Procaine and lidocaine had similar actions. Effects on axonal membrane potential and interaction of the Ca on these derivatives were also investigated. These derivatives decreased the action potential without altering the resting membrane potential and when antagonized with Ca, sciatic nerve action potential was decreased. Procaine and lidocaine also showed the same results.