Abstract
Recent study demonstrated PGE2 receptors in various sites of micturition reflex. The purpose of this study was determination of the role of PGE2 on micturition reflex in conscious rats. Methods: Continuous measurements of micturition were performed in SD male rats (300-450g) using the metabolic cage. Number of micturition (N) and urine volume (V) was calculated. 0.5ml or 4 ml the loxprofen solution (Lox) or distilled water (DW, for control) was given orally. Results: In control (0.5ml P.O.) averaged N in first 4 hours was 3.4 and V was 2.1g. At the same time of following day, Lox (1mg/kg, 0.5ml P.O.) was given. Average N in first 4 hours was 2.6 (75%, P<0.01), and V was 1.4g (63.1%, P<0.01). Averaged N and V of after Lox administration in 24 hours did not change from the control (P=0.77 and P=0.56, respectably). V increased from the control at 8-20 hours after the drug administration. For producing the extra-urination, 4ml of water drinking was performed. In control N in first 4 hours was 4.5 and V was 4.2g after 4ml-distilled water drinking. Lox (1mg/kg, 4 ml P.O.) reduced N in 4 hours to 2.8 (61.1%, P<0.02) and V to 2.6g (61.2%, P<0.01). Averaged N and V in 24 hours did not change from the control (P=0.83 and P=0.98, respectably). Conclusion: Loxonin reduced number of micturition and voiding volume in first 4 hours. PGE2 might be important for the micturition reflex. [Jpn J Physiol 54 Suppl:S195 (2004)]
