Kawana M, Kawana C, Amesara R, Juhn S K, Giebink G S
Otitis Media Research Center, University of Minnesota School of Medicine, Minneapolis.
Ann Otol Rhinol Laryngol. 1994 Oct;103(10):812-6. doi: 10.1177/000348949410301012.
Middle ear inflammation in acute bacterial otitis media is characterized by accumulation of neutrophils in middle ear effusion. Since neutrophils release products that may injure surrounding tissues, we studied the effect of neutrophil metabolic products on middle ear epithelial cells (MEECs) in vitro. Chinchilla MEECs were incubated with phorbol myristate acetate (PMA)-activated human neutrophils or with hydrogen peroxide (H2O2). Cell growth, which was measured by 3H-thymidine incorporation, was inhibited by activated neutrophils and by H2O2. Unstimulated neutrophils, PMA alone, and catalase alone did not affect the viability of MEECs. Catalase, an enzyme that reduces H2O2, partially blocked the inhibitory effect of activated neutrophils and completely blocked the inhibitory effect of H2O2. Inhibition of MEEC metabolism by neutrophil-reactive oxygen species may contribute to epithelial injury, which may prolong the middle ear inflammatory response and lead to chronic tissue damage.
急性细菌性中耳炎的中耳炎症特征是中耳积液中有中性粒细胞积聚。由于中性粒细胞会释放可能损伤周围组织的产物，我们在体外研究了中性粒细胞代谢产物对中耳上皮细胞（MEECs）的影响。将豚鼠MEECs与佛波酯（PMA）激活的人中性粒细胞或过氧化氢（H2O2）一起孵育。通过3H-胸腺嘧啶核苷掺入法测定的细胞生长受到激活的中性粒细胞和H2O2的抑制。未刺激的中性粒细胞、单独的PMA和单独的过氧化氢酶对MEECs的活力没有影响。过氧化氢酶是一种可还原H2O2的酶，它部分阻断了激活的中性粒细胞的抑制作用，并完全阻断了H2O2的抑制作用。中性粒细胞活性氧对MEECs代谢的抑制可能导致上皮损伤，这可能会延长中耳炎症反应并导致慢性组织损伤。
