Further evidence of endogenous hydrogen sulphide as a mediator of relaxation in human and rat bladder

Abstract

We investigated the expression of hydrogen sulphide (H 2 S) in human and rat lower urinary tract (including bladder, prostate and urethra) tissues, and we sought to determine whether H 2 S induces relaxation of human and Sprague-Dawley (SD) rat bladder strips. Human normal lower urinary tract tissue was obtained for the evaluation of endogenous H 2 S productivity using a sulphide-sensitive electrode and for the analysis of the expression levels of all three synthases of endogenous H 2 S, cystathionine β-synthase (CBS), cystathionine γ lyase (CSE) and 3-mercaptopyruvate sulphur transferase (MPST, as known as 3-MST) by Western blot assay. CBS, CSE and MPST were located in human sample slides by immunohistochemistry. Human and male adult SD rat bladder strips were tested for H 2 S function with a transducer and recorded. All experiments were repeated six times. The endogenous H 2 S productivity and the H 2 S synthases had various distributions in the human and rat lower urinary tract tissues and were located in both epithelial and stromal sections. L-cysteine (L-Cys, a substrate of CBS, CSE and MPST) elicited relaxation in a dose-dependent manner on human bladder strips pre-contracted by acetylcholine chloride. This effect could be diminished by the ATP-sensitive potassium ion (K ATP) channel blocker glibenclamide (GLB), the CSE inhibitor DL-propargylglycine (PPG) and the CBS inhibitor hydroxylamine (HA). H 2 S and its three synthases were present in the human and rat lower urinary tract tissues and relaxed human and rat bladder strips, which implied that endogenous H 2 S might play a role in physiological function and pathological disorders of the lower urinary tract symptoms (LUTS) or overactive bladder (OAB). © 2013 AJA, SIMM & SJTU. All rights reserved.