Fig. 5.

Time course of p-DITC-ADAC-induced loss of specific [³H]CPX binding to DDT cells. DDT cells were incubated without (F) or with (f) 1 μM p-DITC-ADAC for the indicated times followed by six washes with HBSS. The cells were then homogenized in 50 mM Tris-HCl buffer, pH 7.4, containing 5 mM MgCl₂, and the suspension was centrifuged at 48,000 × g for 15 min. The membranes were resuspended in buffer, and the A₁-AdoR content was determined with 4 nM [³H]CPX as described in Experimental Prcedures. Points, mean ± standard error of three separate experiments assayed in triplicate. The control specific [³H]CPX binding was 212 ± 30 fmol/mg of protein.