Organo Chlorines

ORGANO CHLORINES

  • Environmental and persistence concern has resulted in declined use of organochlorines

Three groups

  • Cholrinated ethane derivatives, DDT (Dichlorodiphenyl Trichlorethane),DDE (Dichlorodiphenyldichlorethane) and DDD(diclofol, methoxychlor)
  • Cyclodines - chlordane, alderin, dielderin, hepatochlor, endrin and toxaphene(other than DDT)
  • Hexachlorhexanes(HCH) like BHC and which includes γ isomer and lindane

Mode of Action

  • Chlorinated ethanes causes inhibition of Na conductance along sensory and motor nerve fibres by holding sodium channels open - delayed repolarization of axonal membrane - so the nerve becomes vulnerable to repetitive discharge from small stimuli that would normally cause an action potential in fully repolarized neuron
  • Cyclodines 2 modes of action-
    • Inhibition of γ amino butyric acid (GABA) stimulated Cl- flux & interference with Ca + flux
    • The resultant inhibitory post synaptic potential leads to a state of partial depolarization of the post synaptic membrane and vulnerability to repeated discharge
    • Same modeof action  for lendane which binds picrotoxin side of GABA receptor inhibits- GABA dependent Cl flux into the neuron 
Last modified: Tuesday, 10 April 2012, 5:32 AM