['First-line pharmacotherapy for overactive bladder consists of anticholinergics. However, patient compliance is exceptionally low, which may be due to progressive loss of effectiveness.', 'To decipher the involved molecular mechanisms and to evaluate the effects of chronic systemic administration of anticholinergics on bladder function and on muscarinic and purinergic receptors expression in rats.', 'Female Wistar rats were implanted with an osmotic pump that chronically administered vehicle (Vehc), 0.36 mg/kg per day oxybutynin (Oxyc), or 0.19 mg/kg per day fesoterodine (Fesoc) for 28 d.', 'For cystometry experiments, a small catheter was implanted in the bladder.', 'Urologic phenotype was evaluated by the analysis of the micturition pattern and urodynamics. Expression of muscarinic and purinergic receptors was assessed by Western blot analysis of detrusor membrane protein. Functional responses to carbachol and adenosine triphosphate (ATP) were evaluated using muscle-strip contractility experiments.'] Does chronic administration of anticholinergics in rats induce a shift from muscarinic to purinergic transmission in the bladder wall?