PHOTOACTIVATION OF THE NITRIC-OXIDE DONOR SIN-1

This study investigates whether nitric oxide (NO) release from linsido mine (SIN-1), the active metabolite of the antianginal drug molsidomin e, is light sensitive. A 9-h irradiation with polychromatic visible li ght increased the formation of nitrite (NO index metabolite) from SIN- 1 (1 mM) by 61% as compared to control samples incubated in the dark, Under the same conditions (9-h irradiation) the concentration of oxyge n decreased to 2% of control, However, oxygen consumption was substant ially reduced when light was excluded (35% recovery after 9 h), These results show that irradiation with visible light markedly enhances the oxygen-dependent NO release from SIN-1, Thus, sydnonimines appear to be suitable model compounds for the development of photoactivatable NO donors. (C) 1997 Federation of European Biochemical Societies.