Seizure activity produces differential changes in adenosine A1 receptors within rat hippocampus.
Specific ligand binding to rat hippocampal adenosine A1 receptor after administration of the convulsant drug 3-mercaptopropionic acid (MP) was studied by means of a quantitative autoradiographic method. 2-Chloro-N6-[cyclopentyl-2,3,4,5-3H adenosine] ([3H]CCPA), a potent and selective A1 receptor ligand, was selected for binding studies. MP administration (150 mg/kg, i.p.), at seizure, caused significant increases in the following CA1 layers: pyramidal (45%), radiatum (18%) and lacunosum molecular (35%); in CA2 area, a significant decrease in stratum oriens (36%) and an increase in stratum radiatum (14%) and lacunosum molecular (33%) layers was observed. In CA3 area a rise in pyramidal (40%) and radiatum layers (26%), as well as in hillus (97%) was found. At postseizure, changes were restricted to CA1, CA2 and CA3 pyramidal layers and to CA1 lacunosum molecular layer, with increases ranging from 22 to 50%. These results show that [3H]CCPA binding is modified diversely in intrahippocampal layers and areas, thus indicating their dissimilar role in seizure activity.
Vanore
G
G
Instituto de Biologia Celular y Neurociencias Prof. E. De Robertis, Facultad de Medicina, Universidad de Buenos Aires, Argentina.
Giraldez
L
L
Rodríguez de Lores Arnaiz
G
G
Girardi
E
E
D000241:Adenosine / Q000031:analogs & derivatives* / Q000378:metabolism; D000818:Animals; D001345:Autoradiography; D006624:Hippocampus / Q000378:metabolism / Q000503:physiopathology*; D066298:In Vitro Techniques; D008297:Male; D011869:Radioligand Assay; D051381:Rats; D017208:Rats, Wistar; D018047:Receptors, Purinergic P1 / Q000378:metabolism*; D012640:Seizures / Q000378:metabolism*; D014316:Tritium
D018047:Receptors, Purinergic P1; D014316:Tritium; C058394:2-chloro-N(6)cyclopentyladenosine; D000241:Adenosine