Emotional Stress Facilitates Micturition Reflex: Possible Inhibition by an α1-Adrenoceptor Blocker in the Conscious and Anesthetized State

To test the hypothesis that naftopidil prolongs intercontraction intervals in rats undergoing chronic stress as observed in previous animal models, voiding behavior and bladder function were measured and analyzed. Female Sprague-Dawley rats weighing 200-230 g were exposed to repeated variate stress (RVS) for 1 week, chronic variable mild stress for 2 weeks, or simple mild stress for 1 week. Voiding behavior was assessed in metabolic cages. Voiding frequency and urine output were measured, and changes of these values were compared for the different types of stress. Micturition reflex was analyzed using unconscious cystometry. Naftopidil was administered orally at 30 mg/kg/day for 2 weeks. Unexpectedly, no stress-exposed rats exhibited increased micturition frequency compared to the normal nonstressed control. However, intercontraction intervals were shortened with each type of stress in the unconscious condition, especially by RVS (P