CHANGES IN NEUTROPHIL MORPHOLOGY AND MORPHOMETRY FOLLOWING EXPOSURE TO CIGARETTE-SMOKE

Acute cigarette smoking delays neutrophils within the pulmonary circul ation in some smokers. Evidence from an in-vitro Micropore filter mode l of the pulmonary capillaries indicates that this may be due to a smo ke induced decrease in cell deformability. In order to determine wheth er changes in cell shape are associated with the observed decrease in neutrophil deformability following smoke exposure, cell morphology, us ing scanning electron microscopy, and morphometric measurements, made using transmission electron microscopy, were performed on aliquots of neutrophils harvested from whole blood in non-smoking subjects before and after exposure in vitro to cigarette smoke. Smoke exposure increas ed the maximum diameter and circumference of neutrophils, without chan ging their area. There was also a change in the maximum to minimum cel l diameter ratio, which indicated that the cells had become less spher ical. Scanning electron microscopy showed that smoke exposed cells had developed blebbing of their surface membranes, suggestive of an oxida tive injury to the cell membrane rather than the shape changes associa ted with cell activation. These changes in the morphology and morphome try of smoke exposed neutrophils may contribute to the reduction in ce ll deformability induced by cigarette smoke.