Blockers, Na+ channel

MTX caused a contraction of vascular smooth muscle and positive inotropic, positive chronotropic and arrhythmogenic effects on cardiac muscle. The effect of MTX was little affected by various receptor blockers, a Na channel blocker or a catecholamine depleting agent. Further, MTX had no effect on the enzymes which were related to Ca movements, such as Na , K -ATPase, cyclic AMP phosphodiesterase, and sarcoplasmic reticulum Ca -ATPase. These results would eliminate the possible involvement of an indirect action elicited by the release of chemical mediators and direct modifications of their receptors, Na channels, or various enzymes as a major mechanism of action of MTX. 

Lignocaine (lidocaine) A local anaesthetic and voltage-operated Na+ channel blocker. 

Salvati, P., Maj, R., McArthur, R. A., Cervini, M. A., Kozak, W., Benatti, L., Fariello, R. G. PNU-151774E, a novel Na+ channel blocker, shows analgesic effects in some animal models, Soc. Neurosci. Abstr. 1999, 25, 1947. 

Tetrodotoxin (TTX) a voltage-dependent Na+-channel blocker was infused directly into the prefrontal cortex through the dialysis fiber. TTX significantly decreased ACh spontaneous release by more than 40%, but the exposure to 100 mM potassium released similar amounts of ACh in the absence and in the presence of 0.5 pM TTX (figure 2). However, H3 receptor-induced inhibition is... 

IC Na+ channel blocker Markedly siows Phase 0 depolarization... 

Marine rather than terrestrial organisms produce a large variety of structurally intriguing metabolites endowed with guanidine functions [1], The most well known probably are saxitoxin (1), an extremely potent Na" channel blocker, and tetro-dotoxin (2), the powerful poison of the puffer fish family (Scheme 1). 

Voltage-gated Na channels The DDT group, pyrethroids, Sabadilla Indoxacarb Delayed Na inactivation (Na channel modulators) Na channel blocker... 

---