Alkali-degraded cornea generates a low molecular weight chemoattractant for polymorphonuclear leukocytes.

The current study was designed to determine if a polymorphonuclear leukocyte (PMN) chemoattractant is derived from alkali-degraded whole cornea and to establish a range for its molecular weight.We utilized a collagen gel-visual chemotactic assay to quantify the directional movement of PMN exposed to alkali-degraded corneas (30 min or 24 hr). In this experiment, the sample to be tested for chemotactic activity passed through a 14,000 molecular weight cutoff membrane into a collagen gel in which resting neutrophils were suspended in a random fashion. Cell movement was videotaped and subsequently tracked by digitizing the centroid of the cells at 30-sec intervals. Computer analysis of these tracks illustrated many behavioral characteristics, including directional movement.Alkali-degraded whole bovine corneas produced a chemotactic response in neutrophils within 5 min. Dilution of the 24-hr sample to 1:7 yielded a significant chemotactic response. The chemotactic response of both the 30-min and 24-hr samples followed a dose-response curve.This agent may be one of the inflammatory mediators that trigger the early neutrophil response after an alkali-injury to the eye.