[Expression of nitric oxide synthase-2 in specific cells of human glaucomatous optic nerve head]

To investigate the specific cells expressing nitric oxide synthase-2 (NOS-2) in the optic nerve head of patients with primary open angle glaucoma.

Double-labeling immunohistochemistry was used for labeling of NOS-2 and one of the specific cell markers.

NOS-2 was labeled in the astrocytes. The NOS-2 positive astrocytes were mainly located in the damaged area of nerve fibers. A few arteries had NOS-2 labeling in the endothelial cells. There was no significant labeling of NOS-2 in microglia, vascular smooth muscle cells and pericytes.

In glaucomatous optic nerve neuropathy, NOS-2 is mainly expressed by astrocytes. Astrocytes may play an important role in the local neurotoxicity of axons of the ganglion cells by producing excessive nitric oxide.