Within 4 hr after exposure to BSDE, extranuclear cell fluorescence was apparent.
We measured Trypan Blue exclusion in NHBE cells 72 hr after a single exposure to BSDE (Table 1).
Unexposed controls, vehicle controls, and NHBE cells exposed to BSDE for 72 hr were stained with propidium iodide and assayed for the presence of BNCs (Table 2).
Here we continue the physico-chemical characterization of butadiene soot (12) and report our initial observations on the effects of BSDE, a DMSO extract of this soot, on putative targets--NHBE cells.
The wide range of products found in BSDE, including AHs, PAHs, and free radicals, combined with the small size of the generated particles, indicates that inhalation of BSDE could have deleterious health consequences.
The data presented here were derived from one stock preparation of BSDE.
Results of electrochemical studies and those from ESR analysis of ascorbate radicals generated in a dose-dependent manner by BSDE confirmed the presence of pro-oxidant activity.
Cytoplasmic fluorescence was the earliest and most striking response of the cells to BSDE exposure.
However, the absence of cytoplasmic fluorescence in control NHBE cells suggests that their response to BSDE is distinct from the prominent, punctate fluorescence that has been described in mammalian cells and that has been ascribed to lysosomal lipofuscin accumulation (19).
The presence in BSDE of a wide range of AHs and PAHs and of at least one strongly oxidizing component is consistent with these observations--the NHBE cell responses reflect acute oxidative damage.
Although wide differences (1,000-fold) have been reported in the survival of different NHBE strains treated with chemical carcinogens (21,22), here both strains responded very similarly to the single BSDE challenge.
BSDE elicited a dose-dependent increase in BNCs in NHBE cells (Table 2) similar to that observed in the phenotypically altered progeny of NHBE cells exposed to fractionated doses of [alpha]-particles (26).