Potentiation of GABA-activated currents by imidazobenzoimidazole derivative RU-353 in isolated cerebellum Purkinje cells.

Voltage clamp and concentration jump experiments performed on Purkinje cells isolated from rat cerebellum showed that novel imidazobenzoimidazole derivative RU-353 increased the amplitude of GABA-activated chlorine current in a dose-dependent manner (EC50=15 microM for the currents activated by 1 microM GABA). RU-353 shifted the GABA dose-response curve to the left, but produced no effect on the maximum response (EC50 in control and in the presence of 30 microM RU-353 were 6.9 and 2.

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.

Effect of imidazobenzoimidazole derivatives RU-353, RU-563, and lidocaine on cerebral circulation in rats.

We demonstrated a dose-dependent inhibitory effect of novel imidazobenzoimidazole derivatives RU-353 and RU-563 on cerebral blood flow and systemic blood pressure in narcotized rats. The effects of RU-353 increased, while the effect of RU-563 decreased with increasing the dose.

Effects of bradysole and dibasole on cerebral bloodflow under experimental conditions.

Bradysole (1 mg/kg intravenously) induced a moderate increase in cerebral bloodflow and a minor decrease in systemic blood pressure in narcotized rats. These effects were less pronounced compared to the effects of dibasole (bradysole structural analog) in the same dose.