What do we mean by membrane stabilising action of magnesium and lignocaine ?
Posted Mar 03 2010 5:56am
Human body is a collection of trillions of cells. Life is nothing but , a bundle of energy flowing across each of these cells .Every organ has a specailised mode of communication among themselves and others. When a cell is in an excited state , there is a likelihood of spontaneous electrical activity.This can happen in nerve cells, cardiac cells , GI tract, or virtually in any cell which has a porous cell membrane and ionic fluxes across it .
Each cell membrane has a resting membrane potential . It varies between -60 to – 90mv in most cells. When this potential increases there a propensity for arrhythmias in heart and convulsions in the brain , peristalsis in intestines and so on .
Drugs like local anesthetic lignociane acts by blocking the Na+ channels and there by neural activation .Similarly magesium acts on these channels to reduce the excitability of these cells.
We know, the sharp ascending stroke of cellular action potential is mediated by Na + .Blockage of this channel blunts the action potential voltage and thus the early and late after depolarisation is prevented
Magnesium sulphate’s anticonvulsant action is directly attributable to this membrane stabilising action
Thus , membrane stabilising action can be termed as “membrane sedating” action