Hydrogen sulfide inhibits the spontaneous and oxytocin-induced contractility of human pregnant myometrium

Abstract

Hydrogen sulfide (H₂S) is a novel endogenous gaseous signaling transmitter in mammalian tissues including smooth muscle tissues. We investigated the effect of sodium hydrosulfide (NaHS), a H₂S donor, on the contractility of isolated human myometrium strips from term pregnant women who were undergoing labor. Cumulative effects of NaHS on spontaneous and oxytocin-induced contractility were evaluated by using isometric tension recordings. NaHS (0.1 μM–1 mM) concentration dependently inhibited spontaneous contractility of laboring myometrium, with a decrease in amplitude and frequency. NaHS (0.1 μM–1 mM) decreased the frequency but not the amplitude of oxytocin (1 μM)-induced contractions. NaHS-induced relaxation could be prevented by pretreatment with glibenclamide, an inhibitor of K⁺_ATP channels. Thus, NaHS evokes relaxation of human pregnant myometrium, suggesting a possible role of H₂S during human pregnancy.

Keywords:

• Hydrogen sulfide
• myometrium
• pregnancy
• contraction

Acknowledgments

The authors wish to thank the nursing and medical staff of the delivery suite and the patients in Changhai Hospital for their participation. This work is supported by National Natural Science Foundation of China (No. 30971090 and No. 30811120433) and Science and Technology Commission of Shanghai Municipals (09XD1405600).

Declaration of interest: The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the paper.