PREVENTION BY A PURINE ANALOG OF KAINATE-INDUCED NEUROPATHOLOGY IN RAT HIPPOCAMPUS

Systemic injection of kainic acid produces a characteristic regional a nd cellular pattern of neuronal loss in the central nervous system by mechanisms which may be relevant to an understanding of neurodegenerat ive disorders. It has previously been found, by measuring the binding of a glial marker ligand, that analogues of adenosine, such as R-N6-ph enylisopropyladenosine (R-PIA), can prevent kainate-induced damage of the hippocampus at doses as low as 10 mu g/kg, i.p. The use of gliotic markers, however, is open to misinterpretation, and the present work was designed to re-examine purine protection against kainate using his tological methods. The results show that R-PIA, at a dose of 25 mu g/k g i.p. in rats, can protect against the neuronal damage caused by kain ate and that this protection could be completely prevented by the simu ltaneous administration of 1,3-dipropyl-8-cyclopentylxanthine, indicat ing the involvement of adenosine A, receptors in the protection.