Our recent report showed that hydrogen sulfide (H2S) is a possible relaxation factor in the rat bladder. Because we have shown bladder dysfunctions develop in spontaneously hypertensive rats (SHRs), we compared effects of NaHS and GYY4137 (H2S donors) on the bladder contractility and the micturition reflex, and H2S contents in the bladder between 18-week-old male SHRs and normotensive Wistar rats (Wistars). Effects of NaHS (1×10-8 to 3×10-4 M) were evaluated on carbachol (10-5 M)-induced pre-contracted bladder strips. Under urethane-anesthesia, effects of intravesically instilled GYY4137 (10-8 to 10-6 M) on the rat micturition reflex were examined. Tissue H2S contents were measured by the methylene blue method. NaHS-induced maximal relaxation was significantly higher in the strips of Wistars than those of SHRs. GYY4137 significantly prolonged intercontraction intervals in Wistars, but not in SHRs. The H2S content in the bladder of SHRs was significantly higher than that in Wistars. These results suggest that H2S-induced bladder relaxation in SHRs is impaired, which might be a cause of hypertension-mediated development of bladder dysfunctions, thereby resulting in a compensatory increase of the H2S level in the SHR bladder.