Effects of verapamil and amiodarone on sympathoadrenal system and balance of excitatory and inhibitory amino acids in rat medulla oblongata

Bull Exp Biol Med. 2005 Jun;139(6):665-7. doi: 10.1007/s10517-005-0372-5.

Abstract

Local injection of verapamil into ventrolateral region of the medulla oblongata triggered the release of epinephrine. Verapamil increased the total content of norepinephrine and epinephrine by 560% and decreased the content of serotonin by 46%. Verapamil had no effect on norepinephrine/epinephrine and norepinephrine/(norepinephrine+epinephrine) ratios in normal rats. Blockade of K+-channels in the medulla oblongata by local injection of 0.001 mg amiodarone did not change the levels of epinephrine and norepinephrine and norepinephrine/epinephrine and norepinephrine/(norepinephrine+epinephrine) ratios. In the medulla oblongata, verapamil proportionally increased the levels of norepinephrine, dopamine, and L-DOPA. Similarly, amiodarone increased the levels of L-DOPA and dopamine by 2.6 and 3.2 times, respectively. Amiodarone shifted the ratio of neuroactive amino acids towards inhibitory transmitters.

MeSH terms

  • Adrenal Glands / drug effects
  • Adrenal Glands / metabolism*
  • Amiodarone / pharmacology*
  • Animals
  • Calcium Channel Blockers / pharmacology
  • Dopamine / metabolism
  • Epinephrine / metabolism
  • Excitatory Amino Acid Antagonists / metabolism*
  • Excitatory Amino Acids / metabolism*
  • Levodopa / metabolism
  • Male
  • Medulla Oblongata / metabolism*
  • Microinjections
  • Norepinephrine / metabolism
  • Potassium Channel Blockers / pharmacology
  • Random Allocation
  • Rats
  • Rats, Inbred Strains
  • Serotonin / metabolism
  • Sympathetic Nervous System / drug effects
  • Sympathetic Nervous System / metabolism*
  • Verapamil / pharmacology*

Substances

  • Calcium Channel Blockers
  • Excitatory Amino Acid Antagonists
  • Excitatory Amino Acids
  • Potassium Channel Blockers
  • Serotonin
  • Levodopa
  • Verapamil
  • Amiodarone
  • Dopamine
  • Norepinephrine
  • Epinephrine