Figure 3.

Immunization with oxidized elastin impairs contrast sensitivity. (A) Optomotor responses were analyzed in C57BL/6 mice over 6 months. Immunized elastin or oxidized elastin was exposed to 6 months of cigarette smoke. Contrast sensitivity was determined by measuring the contrast threshold at a fixed spatial frequency (0.131 cycles per degree) and speed (12 deg/sec) and expressed as threshold (percent contrast required for perception). We previously determined that this spatial frequency falls within the range of maximal contrast sensitivity for 9-month-old wild-type mice (data not shown). Smoke-exposed mice showed a significant reduction in contrast sensitivity compared with controls raised in room air, which was augmented in mice immunized with oxidized elastin (repeated-measures ANOVA: P = 0.01). (B) Contrast sensitivity of mice from panel A at 6 months was compared with nonimmunized room air–raised and nonimmunized smoke-exposed mice. Contrast sensitivity was affected by smoke exposure and immunization, with the effect of control elastin (P < 0.05) being less severe than that of oxidized elastin (P < 0.0001). Data are expressed as mean ± SEM (n = 5–9 per condition).