The adenosine A2A receptor antagonist ZM241385 enhances neuronal survival after oxygen-glucose deprivation in rat CA1 hippocampal slices.
OBJECTIVE
Activation of adenosine A(2A) receptors in the CA1 region of rat hippocampal slices during oxygen-glucose deprivation (OGD), a model of cerebral ischaemia, was investigated.


METHODS
We made extracellular recordings of CA1 field excitatory postsynaptic potentials (fepsps) followed by histochemical and immunohistochemical techniques coupled to Western blots.


RESULTS
OGD (7 or 30 min duration) elicited an irreversible loss of fepsps invariably followed by the appearance of anoxic depolarization (AD), an unambiguous sign of neuronal damage. The application of the selective adenosine A(2A) receptor antagonist, ZM241385 (4-(2-[7-amino-2-{2-furyl}{1,2,4}triazolo{2,3-a}{1,3,5}triazin-5-ylamino]ethyl)phenol; 100-500 nmolxL(-1)) prevented or delayed AD appearance induced by 7 or 30 min OGD and protected from the irreversible fepsp depression elicited by 7 min OGD. Two different selective adenosine A(2A) receptor antagonists, SCH58261 and SCH442416, were less effective than ZM241385 during 7 min OGD. The extent of CA1 cell injury was assessed 3 h after the end of 7 min OGD by propidium iodide. Substantial CA1 pyramidal neuronal damage occurred in untreated slices, exposed to OGD, whereas injury was significantly prevented by 100 nmolxL(-1) ZM241385. Glial fibrillary acid protein (GFAP) immunostaining showed that 3 h after 7 min OGD, astrogliosis was appreciable. Western blot analysis indicated an increase in GFAP 30 kDa fragment which was significantly reduced by treatment with 100 nmolxL(-1) ZM241385.


CONCLUSIONS
In the CA1 hippocampus, antagonism of A(2A) adenosine receptors by ZM241385 was protective during OGD (a model of cerebral ischaemia) by delaying AD appearance, decreasing astrocyte activation and improving neuronal survival.
Department of Preclinical and Clinical Pharmacology, University of Florence, Florence, Italy.
A M
AM
Pugliese
C
C
Traini
S
S
Cipriani
M
M
Gianfriddo
T
T
Mello
M G
MG
Giovannini
A
A
Galli
F
F
Pedata
D000241:Adenosine / Q000031:analogs & derivatives / Q000494:pharmacology; D058917:Adenosine A2 Receptor Antagonists; D000818:Animals; D001253:Astrocytes / Q000187:drug effects / Q000378:metabolism; D015153:Blotting, Western; D002545:Brain Ischemia / Q000378:metabolism / Q000473:pathology / Q000517:prevention & control*; D015687:Cell Hypoxia; D002470:Cell Survival; D004396:Coloring Agents; D019706:Excitatory Postsynaptic Potentials; D005904:Glial Fibrillary Acidic Protein / Q000378:metabolism; D005947:Glucose / Q000172:deficiency*; D006624:Hippocampus / Q000187:drug effects* / Q000378:metabolism / Q000473:pathology; D007150:Immunohistochemistry; D066298:In Vitro Techniques; D008297:Male; D009474:Neurons / Q000187:drug effects* / Q000378:metabolism / Q000473:pathology; D018696:Neuroprotective Agents / Q000494:pharmacology*; D010100:Oxygen / Q000378:metabolism*; D010627:Phenethylamines / Q000494:pharmacology; D011419:Propidium; D011720:Pyrazoles / Q000494:pharmacology; D011743:Pyrimidines / Q000494:pharmacology; D051381:Rats; D017208:Rats, Wistar; D043705:Receptor, Adenosine A2A / Q000378:metabolism; D013194:Staining and Labeling / Q000379:methods; D013997:Time Factors; D014227:Triazines / Q000494:pharmacology*; D014230:Triazoles / Q000494:pharmacology*
C098657:5-amino-7-(2-phenylethyl)-2-(2-furyl)pyrazolo(4,3-e)-1,2,4-triazolo(1,5-c)pyrimidine; D058917:Adenosine A2 Receptor Antagonists; D004396:Coloring Agents; D005904:Glial Fibrillary Acidic Protein; D018696:Neuroprotective Agents; D010627:Phenethylamines; D011720:Pyrazoles; D011743:Pyrimidines; D043705:Receptor, Adenosine A2A; D014227:Triazines; D014230:Triazoles; C097270:ZM 241385; C061282:2-(4-(2-carboxyethyl)phenethylamino)-5'-N-ethylcarboxamidoadenosine; D011419:Propidium; D005947:Glucose; D000241:Adenosine; D010100:Oxygen; C416650:SCH 442416