The Haldane M-value is the ratio of half-saturation pressures for O2 and CO (PO2/PCO) and is a key value of physiological and pathological models exploring CO metabolism or exposure to CO. Nevertheless, the M-values obtained from different studies and different species appear to be inconsistent. A better estimation of M-values and a consideration of interspecies variation will ensure the accuracy of CO study results and allow reliable models to be constructed. We performed a systematic review and meta-analysis in order to determine and compare M-values according to species and experimental conditions. We used electronic libraries (PubMed/Embase/JSTORE) from 1895 to January 2016. For each article, we collected the following parameters: species, age, temperature, pH, atmospheric pressure, concentration of 2,3-diphosphoglycerate (2,3-DPG) or methemoglobin, and type of hemoglobin. The systematic review found 25 articles addressing the M constant, including 135 with individual data and 51 with mean values concerning mammals, laboratory animals, fish, fetal hemoglobin and invertebrates. M-values at a physiological temperature and pH were assessed only for adult (137 [119–153]) and fetal (135 [112–168]) sheep, dogs (215 [193–218]), mice (194 [118–278]) and rats (191 [177–200]). A correlation between M-values and temperature was confirmed for sheep and horses. A correlation between M-values and pH could not be inferred because there was a lack of data. M-values varied according to species. Only the influence of temperature was confirmed. A formal measurement of the M constant in the given experimental conditions should be performed for each animal model study of CO. Further homogeneous studies are necessary to compare the M-values of different animals.

中文翻译：

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动物世界中血红蛋白对一氧化碳的相对亲和常数 (M) 的报告：基于系统评价的元分析比较评价

Haldane M 值是 O2 和 CO 的半饱和压力之比 (PO2/PCO)，是探索 CO 代谢或 CO 暴露的生理和病理模型的关键值。然而，从不同研究中获得的 M 值并且不同的物种似乎不一致。更好地估计 M 值和考虑种间变异将确保 CO 研究结果的准确性并允许构建可靠的模型。我们进行了系统回顾和荟萃分析，以便根据物种和实验条件确定和比较 M 值。我们使用了 1895 年至 2016 年 1 月的电子图书馆（PubMed/Embase/JSTORE）。对于每篇文章，我们收集了以下参数：物种、年龄、温度、pH、大气压力、2,3-二磷酸甘油酸 (2, 3-DPG) 或高铁血红蛋白，以及血红蛋白的类型。系统评价发现了 25 篇关于 M 常数的文章，其中 135 篇是个体数据，51 篇是关于哺乳动物、实验动物、鱼类、胎儿血红蛋白和无脊椎动物的平均值。仅对成年 (137 [119–153]) 和胎儿 (135 [112–168]) 绵羊、狗 (215 [193–218])、小鼠 (194 [118– 278]）和大鼠（191 [177-200]）。绵羊和马的 M 值与温度之间存在相关性。由于缺乏数据，无法推断 M 值与 pH 值之间的相关性。M 值因物种而异。仅确认了温度的影响。对于 CO 的每个动物模型研究，应在给定的实验条件下对 M 常数进行正式测量。