The effect of nitric oxide on the contractile tone of Muller cells

The effect of nitric oxide (NO) on the contractile tone of Muller cells was investigated. Muller cells, isolated from the retina of chick embryos, wer e cultured on thin sheets of silicone. S-Nitro-N-acetyl-DL-penicillamine (S NAP), an NO donor, was applied in the presence or the absence of carboxyl p henyltetramethylimidazole oxide (C-PTIO), an NO scavenger. The contractile tone of Muller cells was assessed by the extent of wrinkles created on the silicone sheets. The change of contractile tone was evaluated quantitativel y by digitizing the photograph before and after the application of SNAP. Re laxation of wrinkles was induced by SNAP. C-PTIO inhibited the SNAP-induced relaxation of wrinkles. These results suggest that NO affects the contract ility of embryonic Muller cells and could thus modulate ocular development.