Introduction
Whether carbon dioxide (CO2) affects systemic oxidative phenomena under conditions of endotoxemia is not sufficiently clarified. The study aimed to assess the impact of moderate acute hypercapnia on the respiratory burst of circulating neutrophils in mechanically ventilated endotoxemic rabbits.

Material and methods
Twenty-four endotoxemic rabbits were mechanically ventilated with standard or CO2‑enriched gas mixture in order to obtain isooxic hypercapnia. At a baseline point and following 180 min of hypercapnic ventilation, luminol-dependent chemiluminescence (CL) of circulating neutrophils and serum 2-thiobarbituric acid reactive substance (TBARS) concentrations were measured. Throughout the study, leukocyte and neutrophil counts, pH status, circulatory parameters and body temperature were also assessed.

Results
Following 180 min of hypercapnic ventilation, opsonized zymosan (OZ)-stimulated neutrophils showed lower CL vs. the control group (p = 0.004). Other parameters studied were not affected.

Conclusions
Short-term isooxic hypercapnia in endotoxemic rabbits preserves circulating neutrophil count pattern and reactive oxygen species (ROS) generation, but it may reduce phagocytosis.



中文翻译：

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急性等氧高碳酸血症对内毒素兔全身中性粒细胞氧化活性的影响

引言
二氧化碳 (CO2) 是否会影响在内毒素血症条件下的全身氧化现象尚未得到充分阐明。该研究旨在评估中度急性高碳酸血症对机械通气内毒素血症兔循环中性粒细胞呼吸爆发的影响。

材料与方法
用标准或富含二氧化碳的气体混合物对 24 只内毒素血症家兔进行机械通气，以获得等氧性高碳酸血症。在基线点和高碳酸血症通气 180 分钟后，测量循环中性粒细胞的鲁米诺依赖性化学发光 (CL) 和血清 2-硫代巴比妥酸反应物质 (TBARS) 浓度。在整个研究过程中，还评估了白细胞和中性粒细胞计数、pH 状态、循环参数和体温。

结果
在 180 分钟的高碳酸血症通气后，调理酵母聚糖 (OZ) 刺激的中性粒细胞与对照组相比显示出较低的 CL (p = 0.004)。研究的其他参数不受影响。

结论
内毒素血症兔的短期等氧性高碳酸血症保留了循环中性粒细胞计数模式和活性氧 (ROS) 生成，但它可能会降低吞噬作用。