Valerian Extract Ze 911 Inhibits Postsynaptic Potentials by Activation of Adenosine A1 Receptors in Rat Cortical Neurons

Abstract

In this study we evaluated the adenosine A₁ receptor-mediated effect of valerian extract (Ze 911) on postsynaptic potentials (PSPs) in pyramidal cells of the rat cingulate cortex in a slice preparation. We first observed that N ⁶-cyclopentyladenosine (CPA, 0.01 - 10 μM), an adenosine A₁ receptor agonist, inhibited PSPs in a concentration-dependent manner. The CPA (10 μM)-induced inhibition was antagonized by 1,3-dipropyl-8-cyclopentylxanthine (DPCPX, 0.1 μM), an adenosine A₁ receptor antagonist. Ze 911 concentration dependently (0.1 - 15 mg/mL) inhibited PSPs in the presence of the adenosine A_2A receptor antagonist 1,3,7-trimethyl-8-(3-chlorostyryl)xanthine (CSC, 0.2 μM) and adenosine deaminase (1 U/mL). The maximal inhibition induced by 10 mg/mL was completely antagonised by DPCPX (0.1 μM), an A₁ receptor blocker. The data suggest that activation of adenosine A₁ receptors is involved in the pharmacological effects of the valerian extract Ze 911.

Key words

Adenosine - adenosine A₁ receptor - valerian - postsynaptic potential - pyramidal cells

References

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