Aim:To explore the effects and mechanisms of caffeine and coffee on bladderdysfunction in streptozotocin-induced diabetic rats.Methods:Sprague-Dawleymale rats were divided randomly into 4 groups:control,diabetes mellitus(DM),DM with coffee treatment,and DM with caffeine treatment.The diabetic rat wasinduced by intraperitoneal injection of streptozotocin(60 mg/kg).After 7 weeks oftreatment with coffee and caffeine,cystometrogram,contractile responses to elec-trical field stimulation(EFS)and acetylcholine(ACh),and cyclic AMP(cAMP)concentration of the bladder body and base were measured.Results:The bladderweight,volume threshold for micturition and post-void residual volume(PVR)inthe diabetic rats were significantly higher compared to those in the control animals.Coffee or caffeine treatment significantly reduced the bladder weight,bladdercapacity and PVR in the diabetic rats.DM caused significant decreases in cAMPconcentration of the bladder and coffee and caffeine caused upregulation of cAMPcontent in the diabetic bladder.In addition,coffee and caffeine tended to normal-ize the altered detrusor contractile responses to EFS and ACh in the diabetic rats.Conclusion:These results indicate that caffeine and coffee may have beneficialeffects on bladder dysfunction in the early stage of diabetes by increasing cAMPcontent in the lower urinary tract,recovering the micturition reflex and improvingthe detrusor contractility. Aim: To explore the effects and mechanisms of caffeine and coffee on bladder dysfunction in streptozotocin-induced diabetic rats. Methods: Sprague-Dawleymale rats were divided randomly into 4 groups: control, diabetes mellitus (DM), DM with coffee treatment, and DM with caffeine treatment. The diabetic rat was induced by intraperitoneal injection of streptozotocin (60 mg / kg). After 7 weeks of treatment with coffee and caffeine, cystometrogram, contractile responses to elec-trical field stimulation (EFS) and acetylcholine (ACh) Results: The bladder weight, volume threshold for micturition and post-void residual volume (PVR) inthe diabetic rats were significantly higher than those in the control animals.Coffee or caffeine treatment reduced the bladder weight, bladder capacity and PVR in the diabetic rats. DM caused significant reduction in cAMPconcentration of the bladder and coffee and caffeine caused upregulation of cAMPcontent in the diabetic bladder. In addition, coffee and caffeine tended to normal-ize the altered detrusor contractile responses to EFS and ACh in the diabetic rats. Conlusion: These results indicate that caffeine and coffee may have beneficialeffects on bladder dysfunction in the early stage of diabetes by increasing cAMPcontent in the lower urinary tract, recovering the micturition reflex and improvingthe detrusor contractility.