[3H]U69,593 saturation binding results ex vivo with mouse brain membranes pretreated in vivo with saline or nor-BNI
Mice were pretreated once with saline or the opioid receptor antagonist nor-BNI (10 mg/kg i.p.). Brain membranes were harvested 1, 7, or 14 days post-treatment followed by two centrifugal washes. Membranes were finally resuspended in 50 mM Tris-HCl, pH 7.4, and [3H]U69,593 saturation binding at concentrations of 0.05–6.4 nM was measured as described under Materials andMethods. Data are expressed as mean value ± S.E.M. for three determinations performed in triplicate.