The Effects of Oxytocin on Stressed Rats with Increased Urinary Frequency

Psychological stress exacerbates lower urinary tract symptoms (LUTS), including urinary frequency and bladder hypersensitivity. This study aimed to determine whether chronic oxytocin (OXT) administration mitigates stress-induced bladder dysfunction and modulates central stress pathways. Female Sprague–Dawley rats were assigned to control, stress, or stress/OXT groups (n = 14 each) and exposed to repeated variable stress (RVS) for one week. Mechanical sensitivity, cystometric parameters, plasma catecholamines and cortisol, bladder histology, paraventricular nucleus (PVN) c-Fos expression, and gene expression in bladder and brain regions were evaluated. RVS induced mechanical hypersensitivity, shortened intercontraction intervals, increased bladder weight, and elevated plasma adrenaline, dopamine, and cortisol levels. Bladder epithelial thickening, submucosal nerve hyperplasia, and upregulation of EP3 and ENaC were also observed. Stress significantly increased PVN activation and upregulated ChAT, CRF, and TH expression in the brainstem. OXT treatment normalized intercontraction intervals, reduced catecholamine and cortisol levels, attenuated PVN c-Fos activation, and increased OXTR and GAD expression in the hypothalamus and thalamus. IL-6 expression was unchanged by stress but decreased by OXT. Chronic OXT administration was associated with improvement of stress-induced urinary frequency and was associated with modulation of central stress pathways, with limited evidence of direct peripheral anti-inflammatory effects.