Effect of experimental pathologies on the density of urinary bladder muscarinic receptor subtypes. M2 and M3 receptors were labeled with [3H]QNB and solubilized as described in Luthin et al. (19). Data shown are average fmol (±SE) of receptor/mg solubilized protein from sham operated, DIV, DIV-DEN, DEN, BOO, and MPG-DEC (n = 4–5 determinations from 6–18 bladders). Protein concentration in the solubilized receptor preparation was ~8% of the protein concentration in the crude homogenate. Compared with filtration binding, ~50% of the muscarinic receptors were solubilized (data not shown). Group differences were determined using ANOVA with a post hoc Newman-Keuls test. For total receptor density all groups are different from each other. For M2 receptor density, all groups are different from each other. For M3 receptor density, sham operated is different from DIV, DIV-DEN, DEN, and BOO.