Ultrastructural analysis of leukocytes recruited into the guinea pig lung by LTB4 aerosol

Two groups of naive guinea pigs were exposed to different LTB4 aerosol solutions: LTB4/saline and LTB4/BSA. Control animals were exposed to saline alone and saline/BSA. The LTB4/BSA aerosol was the most effective in recruiting leukocytes, with the maximal numbers of cells in the lung tissue at 6 hrs. Light microscopy/TEM revealed marked differences in eosinophil morphology in saline/BSA and LTB4/BSA aerosol treated animals. Occasional eosinophils in the submucosa of controls, had few pseudopodia, few cytoplasmic vesicles, and intact granules. In LTB4 treated animals, there were numerous eosinophils in the bronchial mucosa and submucosa with numerous pseudopodia, numerous cytoplasmic vesicles, and light crystalline cores.