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