Overactive bladder (OAB) is a symptomatic disorder of increased urgency, frequency, and nocturia, with or without incontinence. OAB patients demonstrate atropine-resistant nerve-mediated contractions mediated by ATP, especially significant at low stimulation frequencies, and which may contribute to the pathology. Adenosine (Ado), a metabolite of ATP, may mediate some of the contractile changes associated with OAB. We examined the effect of Ado and Ado receptor (AR) ligands on contractile responses from detrusor from patients with stable and neuropathic detrusor overactivity (NDO), as well as the AR expression profiles in these two cohorts. Bladder biopsies obtained from patients were: i) Stable bladders; bladder carcinoma undergoing cystectomy (n=16: 9 female; 7 male; 56±14yr); ii) NDO; spinal cord injury or multiple sclerosis undergoing clam ileocystoplasty (n=18: 8 female; 10 male; 33±7yr). Some biopsies had more than one preparation (n). In vitro isometric tension was elicited by carbachol (CCh, 1 µM) or electrical field stimulation (EFS: 0.1ms pulse width, 3s stimulation every 90s, 40-50V). The effects of Ado and AR ligands were measured as a mean percentage reduction from average pre- and post-control values. Profiles of AR (A1,A2A,A2B,A3) transcripts and protein expression were done by RT-PCR and Western blot. Data sets are expressed as means±SD and compared by ANOVA and parametric post hoc tests. The null hypothesis was rejected if p<0.05. Ado (1 mM; pIC50 3.65-3.70) attenuated CCh equivalently in detrusor from stable and NDO bladders (38.1±2.0%; 41.5±3.7% respectively, n=19,10). With EFS contractions at 40Hz (T40) a similar reduction was measured (38.0±9.9%; 48.5±15.6%, n=36,23). At 4Hz (T4) the effect was significantly greater in NDO bladders (38.0±9.0%; 83.1±6.7%, n=36,23). The A1/A2-receptor agonist NECA was much less effective in stable bladder and had no effect in NDO bladders. For stable bladders, tension was reduced by 12.2±2.6%, 12.2±2.6% and 13.9±2.4% for CCh, T40 and T4 contractions (n=30,14,14). The actions of NECA were abolished by the A2B-receptor antagonist alloxazine (1 µM). The A1-selective agonist, CPA had no effect on stable detrusor but attenuated T40 and T4 contractions in NDO detrusor (31.6±10.5, 72.3±24.0 respectively, n=17,17). AR subtype transcription was similar in stable and NDO bladders, except reduced A2A levels in NDO bladders. Ado reduced nerve-mediated and CCh-induced contractions, only partially mirrored by an A1/2-selective agonist NECA, through A2B receptors (A3-receptor agonists had no effect, not shown). The A1-receptor agonist CPA affected only nerve-mediated contractions, especially at low frequencies in NDO bladders. We propose that Ado attenuated directly detrusor contractility by pathways independent of A-receptors and also preferentially attenuated ATP release from efferent nerves via A1 receptors.