Proceedings of The Physiological Society

University of Edinburgh (2007) Proc Physiol Soc 6, C4

Oral Communications

Production of Hydrogen Sulphide in Intrauterine Tissues.

P. Patel1, M. Vatish2, J. Heptinstall1, R. Wang3, R. J. Carson1

1. Biomolecular Sciences, Coventry University, Coventry, United Kingdom. 2. Molecular Medicine Research Group, University of Warwick, Coventry, United Kingdom. 3. Lakehead University, Thunder Bay, ON, Canada.

Hydrogen sulphide (H2S) is a gasotransmitter which is produced endogenously from L-cysteine via the enzymes cystathionine β-synthase (CBS) and cystathionine γ-lyase (CSE) (Zhao et al., 2003). The possible role of hydrogen sulphide in reproduction has not yet been fully investigated. Sidhu et al. (2001) previously demonstrated that H2S relaxed uterine smooth muscle in vitro. The aim of the present study was to investigate the endogenous production of H2S in rat and human intrauterine tissues in vitro. The expression of CBS and CSE was also investigated in rat and human intrauterine tissues, using Western blotting. Basal production rate of H2S was measured in rat and human intrauterine tissue homogenates using a standard methylene blue assay technique, involving the trapping of yielded H2S as zinc sulphide (Zhao et al., 2003). The effects of nitric oxide (NO) and hypoxia on the endogenous production rates of H2S were also investigated. The order of H 2S production rates (mean ± SD, n = 4) for rat tissue was: rat liver (positive control) (777 ± 165 mmol/min/g) > rat uterus (168 ± 102 mmol/min/g) > rat fetal membranes (22.3 ± 15.2 mmol/min/g) > rat placenta (11.1 ± 4.7 mmol/min/g), compared to human placenta (200 ± 103 mmol/min/g). NO significantly increased H2S production in rat fetal membranes (P<0.05). Under hypoxic conditions the production of H2S was significantly elevated in human placenta, rat liver, uterus and fetal membranes (P<0.05). Western blotting (n = 4) detected the expression of CBS and CSE in all rat intrauterine tissues, and in human placenta, myometrium, amnion and chorion. Rat and human intrauterine tissues produce H2S in vitro possibly via CBS and CSE enzymes. NO increased the production of H2S in rat fetal membranes. The augmentation of H2S production in human intrauterine tissues by hypoxia could have a pathophysiology role. Reference 1 : Sidhu, R., Singh, M., Samir, G. and Carson, R. J. (2001) L-Cysteine and Sodium Hydrosulphide Inhibit Spontaneous Contractility in Isolated Pregnant Uterine Strips in Vitro. Pharmacology & Toxicology 88, (4) 198-203.Reference 2 : Zhao, W., Ndisang, J. F. and Wang, R. (2003) Modulation of endogenous production of H2S in rat tissues. Canadian Journal of Physiology and Pharmacology 81, 848-853

Where applicable, experiments conform with Society ethical requirements