Figure 1.

Effects of various drugs on the binding of 500 pM [³H]-silodosin (a) and 300 pM [³H]-prazosin (b) in intact segments of rat cerebral cortex. The concentrations of drugs used are as follows: 30 μM phentolamine, 1 μM tamsulosin, 1 μM silodosin, 1 μM prazosin, 100 μM adrenaline, 100 μM noradrenaline and 0.01% ascorbic acid. Adrenaline and noradrenaline were incubated in the presence of 0.01% ascorbic acid. ‘Total' indicates the binding in the absence of any drugs. Binding capacity, fmol per mg total tissue protein, was calculated from the specific activity of each radioligand. The results shown are the mean±s.e.mean of 4–5 determinations.