title: The selective A2A receptor antagonist SCH 58261 reduces striatal transmitter outflow, turning behavior and ischemic brain damage induced by permanent focal ischemia in the rat.
abstract: Adenosine A(2A) receptor antagonists have been proved protective in different ischemia models. In this study we verified if the protective effect of the selective A(2A) antagonist, SCH 58261, could be attributed to the reduction of the excitatory amino acid outflow induced by cerebral focal ischemia. A vertical microdialysis probe was inserted into the striatum of male Wistar rats and, after 24 h, permanent right intraluminal middle cerebral artery occlusion (MCAo) was induced. Soon after waking, rats showed a definite contralateral turning behavior, which persisted up to 7 h after MCAo. During 4 h after MCAo, glutamate, aspartate, GABA, adenosine and taurine outflow increased. SCH 58261 (0.01 mg/kg, i.p.), administered 5 min after MCAo, suppressed turning behavior and significantly reduced the outflow of glutamate, aspartate, GABA and adenosine. At 24 h after MCAo, the rats showed severe sensorimotor deficit and damage in both the striatum and cortex. SCH 58261 significantly reduced cortical damage but did not protect against the sensorimotor deficit. The protective effect of SCH 58261 against turning behavior and increased outflow of excitatory amino acids in the first hours after MCAo suggests the potential utility of selective adenosine A(2A) antagonists when administered in the first hours after ischemia. Furthermore, this study, for the first time, proposes that turning behavior after permanent intraluminal MCAo, be used as a precocious index of neurological deficit and neuronal damage.
authors.affiliation: Department of Preclinical and Clinical Pharmacology, University of Florence, V le Pieraccini 6, 50139, Florence, Italy.
authors.forename: Alessia
authors.initials: A
authors.lastname: Melani
authors.forename: Leonardo
authors.initials: L
authors.lastname: Pantoni
authors.forename: Francesca
authors.initials: F
authors.lastname: Bordoni
authors.forename: Marco
authors.initials: M
authors.lastname: Gianfriddo
authors.forename: Loria
authors.initials: L
authors.lastname: Bianchi
authors.forename: Maria Giuliana
authors.initials: MG
authors.lastname: Vannucchi
authors.forename: Rosalia
authors.initials: R
authors.lastname: Bertorelli
authors.forename: Angela
authors.initials: A
authors.lastname: Monopoli
authors.forename: Felicita
authors.initials: F
authors.lastname: Pedata
mesh_terms: D000818:Animals; D002545:Brain Ischemia / Q000188:drug therapy / Q000378:metabolism* / Q000473:pathology; D003342:Corpus Striatum / Q000187:drug effects* / Q000378:metabolism; D008297:Male; D009043:Motor Activity / Q000187:drug effects*; D018377:Neurotransmitter Agents / Q000378:metabolism*; D058915:Purinergic P1 Receptor Antagonists; D011743:Pyrimidines / Q000494:pharmacology* / Q000627:therapeutic use; D051381:Rats; D017208:Rats, Wistar; D043705:Receptor, Adenosine A2A; D018047:Receptors, Purinergic P1 / Q000378:metabolism; D014230:Triazoles / Q000494:pharmacology* / Q000627:therapeutic use
chemical_list: C098657:5-amino-7-(2-phenylethyl)-2-(2-furyl)pyrazolo(4,3-e)-1,2,4-triazolo(1,5-c)pyrimidine; D018377:Neurotransmitter Agents; D058915:Purinergic P1 Receptor Antagonists; D011743:Pyrimidines; D043705:Receptor, Adenosine A2A; D018047:Receptors, Purinergic P1; D014230:Triazoles