Guinea pig lung eosinophil: purification and prostaglandin production

Guinea pig lung eosinophils have been purified from bronchoalveolar lavage (BAL) fluid, and the production of prostaglandin E2 (PGE2), thromboxane B2 (TXB2), and 6-keto-PGF1 alpha was measured after stimulation with phorbol myristate acetate (PMA), platelet-activating factor (PAF), and formyl-methionyl-leucyl-phenylalanine (fMLP). A combination of plating and discontinuous Percoll gradient centrifugation was used to purify eosinophils. The purity of eosinophils in fraction E (interface between Percoll density 1.057-1.068) was around 96%, and the viability was 99%, with a mean yield of 2.7 x 10(6) cells per guinea pig. Similarly, in fraction D (interface between Percoll density 1.047-1.057), the mean purity of eosinophils was 76% and the viability of cells was 99%, with a mean yield of 1.1 x 10(6) cells per guinea pig. Purified eosinophils produced TXB2 predominantly after stimulation with PMA, fMLP, and PAF. The 6-keto-PGF1 alpha was slightly increased in cell supernatants after stimulation with PMA and fMLP, but PGE2 was not elevated with any stimulus. The highly purified eosinophils of fraction E generated amounts of TXB2 and 6-keto-PGF1 alpha similar to the amount generated by eosinophils contaminated with some macrophages (fraction D). These results suggest a role for eosinophils in the production of TXA2 by guinea pig lung.