CELL-DAMAGE INDUCED BY ANGIOVIST-970 AND 308NM EXCIMER-LASER RADIATION

Background and Objective: Radiographic contrast media containing iodin e-labeled organic compounds can be present in the irradiated field dur ing laser angioplasty using 308 nm excimer laser radiation. These comp ounds absorb light at 308 nn and may undergo photochemical reactions t hat produce products that damage cells. Study Design/Materials and Met hods: This study was undertaken to determine whether photoproducts tha t damage human lymphocytes in vitro are formed when Angiovist 370 (AV) , a contrast medium containing triiodinated aromatic compounds, is exp osed to 308 nm radiation. Results: The absorption spectrum of AV devel oped a new peak at 360 nn that extended to wavelengths greater than 50 0 nn when dilute AV solutions were exposed to 308 nm radiation indicat ing that photoproducts were formed. Irradiating dilute AV solutions ab ove a layer of human lymphocytes caused a dose-dependent decrease in t hymidine incorporation using fluence rates between 5.2 x 10(6) and 1.0 x 10(8) W/cm(2). Decreased DNA synthesis was independent of the pulse length (10 ns vs. 230 ns) but was lower, at a given dose, when the hi ghest fluence rate was used. Incubation of lymphocytes with preirradia ted AV solutions also decreased incorporation of thymidine in a radiat ion dose-dependent manner. The cell damaging photoproducts in preirrad iated AV solutions were unstable; within 15 min, the effectiveness had decreased by similar to 85%. Conclusions: These results indicate that exposure of AV to 308 nn excimer laser radiation produces photochemic al products that damage human cells in vitro. (C) 1997 Wiley-Liss, Inc .