Sensory pudendal nerve stimulation increases bladder capacity through sympathetic mechanisms in cyclophosphamide‐induced cystitis rats

Aims Interstitial cystitis and bladder pain syndrome is a prevalent health concern with inadequate treatments. Neuromodulation has emerged as a therapeutic option to treat patients refractory to standard care. The objective of this study was to determine the efficacy and mechanism(s) of sensory pudendal nerve stimulation on bladder function in cystitis rats. Methods Female rats were administered saline (n = 8) or cyclophosphamide (CYP, 150 mg/kg IP, n = 16) and single‐trial cystometry experiments were conducted under urethane anesthesia 48 h after injection. Electrical stimulation (0.02‐0.22 mA, 10‐20 Hz) was delivered to the sensory branch of the pudendal nerve and its effect on the bladder and external urethral sphincter were measured. Stimulation trials were also conducted following bilateral hypogastric nerve transection (HGNT) or pharmacological inhibition of beta‐adrenergic receptors (propranolol, 1 mg/kg IV) to determine the mechanisms of bladder inhibition. Results CYP‐induced cystitis decreased bladder capacity (P = 0.0352) and bladder compliance (P = 0.024) by up to 38% of control. Electrical stimulation of the sensory pudendal nerve increased bladder capacity (P