Effects of Hydrogen Sulfide and Nitric Oxide on the Permeability of Cultured Trabecular Meshwork Cells

ABSTRACT

PURPOSE: To investigate the effects of hydrogen sulfide (H₂S) on the permeability of a cultured human trabecular meshwork cells (HTMC) monolayer and its interaction with nitric oxide (NO).METHODS: After exposing primary cultured HTMCs to 0, 50, 100, and 500 µM sodium hydrogen sulfide (NaHS) for 6 hours, the permeabilities through the HTMC monolayer were measured using a Transwell assay with carboxyfluorescein. The production of NO and eNOS mRNA expression were assessed using the Griess assay and reverse transcription-polymerase chain reaction, respectively. In addition, 0, 1, and 10 µM NaHS and 10 µM sodium nitroprusside (SN) were co-exposed to evaluate the possible synergistic effect of H₂S and NO.RESULTS: Greater than 100 µM NaHS increased the permeability through the HTMC monolayer in a dose-dependent manner (p < 0.05). These increased permeabilities were not accompanied by NO production or eNOS mRNA expression (p > 0.05). When 0, 1, and 10 µM NaHS and 10 µM SN were exposed together, there was no significant change of permeability, NO production, or eNOS mRNA expression (all, p > 0.05).CONCLUSIONS: NaHS at high concentrations increased the permeability of the HTMC monolayer, which was not affected by NO. NaHS at low concentrations did not show a synergistic effect with NO. Thus, H₂S at high concentrations may increase trabecular outflow, which may not be associated with NO.