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

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.

Effect of nonselective beta-adrenoblockers on the state of sympathoadrenal system and ratio of neuroactive amino acids in rat medulla oblongata.

Experiments on rats showed that injection of propranolol into the medulla oblongata increased the contents of epinephrine, norepinephrine, dopamine, and L-DOPA by 3.76, 1.4, 2.