Hydrogen sulfide donors – Differential effects of different donors in paraventricular nucleus of the hypothalamus

Abstract

Several hydrogen sulfide (H2S) donors have been produced for commercial use, all of which have been assumed to have similar if not identical effects in their ability to deliver H2S. The identification of H2S‐catalyzing enzymes in the paraventricular nucleus of the hypothalamus (PVN) led us to examine the effects of sodium hydrogen sulfide (NaHS) on the excitability of PVN neurons. Bath application of 50 and 10mM caused 75% of responsive neurons to hyperpolarize (n=28, −13.58±1.51mV), while at 1 and 0.1mM 75% neurons depolarized (n=8, 9.627±2.82mV ). The lack of commercial availability of this donor led us to continue our experiments using sodium hydrosulfide hydrate (NaHS•XH20). Administration of NaHS•XH20 across all concentrations (50, 10, 1, and .1mM) caused 95% of responsive neurons to depolarize (n=37, 10.21±1.33mV). These data show that the administration of NaHS and NaHS•XH20, especially at high concentrations produces different effects in the PVN. While we do not yet know the reason for this difference, these observations may provide some explanation for the different physiological effects of various H2S donors reported in the literature.