In-vivo radiolabelled oxiracetam binding to rat brain.
The in-vivo binding of [3H]oxiracetam has been studied in brain areas of rats examined 30 min after i.c.v. injection. Soluble radioactivity accounted for more than 90% of total radioactivity in all the structures considered and was not affected by co-injection with a 1000-fold excess of unlabelled oxiracetam. Both total and bound radioactivity showed a marked regional distribution, with highest concentrations in the septum, followed by the hippocampus; the cerebral cortex, striatum and cerebellum had the lower concentrations of radioactivity. Computer-assisted quantitative autoradiography with [14C]oxiracetam confirms these findings. Analysis of [3H]oxiracetam bound to membranes indicated that, after co-injection with a 1000-fold excess of unlabelled oxiracetam, there was a significant reduction of binding only in the septum, hippocampus and cerebral cortex. These results suggest that in those cerebral structures oxiracetam binds to saturable sites.
Mennini
T
T
Istituto di Ricerche Farmacologiche Mario Negri, Milan, Italy.
Taddei
C
C
Cagnotto
A
A
Ponzio
F
F
D000818:Animals; D001345:Autoradiography; D001921:Brain / Q000033:anatomy & histology / Q000378:metabolism*; D007276:Injections, Intraventricular; D008297:Male; D011759:Pyrrolidines / Q000493:pharmacokinetics*; D051381:Rats; D011919:Rats, Inbred Strains
D011759:Pyrrolidines; C040619:oxiracetam