Brain tissue hydrolysate acts on presynaptic adenosine receptors in the rat hippocampus.
Adenosine is a potent inhibitory modulator in the brain. It suppresses glutamatergic synaptic transmission and possibly acts as a brain endogenous neuroprotective agent. In this study we have examined the effects of a clinically used porcine brain tissue hydrolysate, Cerebrolysin, on synaptic transmission in the CA1 area of rat hippocampal slices. A major effect of the drug at doses approximating those administered clinically to demented patients was a depression of synaptic transmission at the Schaffer collateral-commissural pathway in CA1. Detailed analysis showed that the inhibition is presynaptic and can be reduced by low doses of a specific blocker of adenosine A1 receptors, 8-cyclopentyltheophylline. Because Cerebrolysin does not contain a detectable amount of adenosine, the effect on adenosine A1 receptors must be indirect, perhaps by release of the endogenous agonist. This action of Cerebrolysin is consistent with a putative neuroprotective action underlying its clinical usage.
Xiong
H
H
Department of Physiology, University of Toronto, ON, Canada.
Wojtowicz
J M
JM
Baskys
A
A
D000241:Adenosine / Q000494:pharmacology; D000596:Amino Acids / Q000494:pharmacology*; D000818:Animals; D006624:Hippocampus / Q000187:drug effects*; D017729:Presynaptic Terminals / Q000187:drug effects; D051381:Rats; D017208:Rats, Wistar; D018047:Receptors, Purinergic P1 / Q000187:drug effects*; D013806:Theophylline / Q000031:analogs & derivatives / Q000494:pharmacology; D013997:Time Factors
D000596:Amino Acids; D018047:Receptors, Purinergic P1; C053907:8-cyclopentyl-1,3-dimethylxanthine; C006952:cerebrolysin; D013806:Theophylline; D000241:Adenosine