Effect of nitric oxide on the proliferation of cultured porcine trabecular meshwork cells.

To investigate the effect of nitric oxide (NO) on the proliferation of trabecular meshwork (TM) cells, primarily cultured porcine TM cells were exposed to NO donor (SNAP, S-nitroso-N-acetyl-D,L-penicillamine) with and without its inhibitor (L-NAME, Nomega-Nitro-L-arginine methyl ester). The proliferation of TM cells was quantified by a rapid colorimetric assay. Acridine orange/Hoechest 33342 staining and flow cytometry with annexin-PI were done. As a result, NO inhibited the proliferation of TM cells significantly in a dose-dependent manner and this inhibitory effect was abolished by L-NAME. Fluorescent microscopy and flow cytometric analysis revealed that NO induced apoptotic cell death. The current results suggest that NO inhibit the proliferation of TM cells and apoptosis may be involved in some degree.