Bland D K, Holland R A
Respir Physiol. 1977 Dec;31(3):279-90. doi: 10.1016/0034-5687(77)90071-8.
Oxygen carriage and 2,3-diphosphoglycerate (2,3-DPG) levels have been measured in the blood of seven species of Australian marsupials ranging in size from 35 to 0.03 kg. They were Red and Grey Kangaroos, Wallaroo, Tammar Wallaby, Brush-tailed possum, Potoroo, and Brown Marsupial Mouse. Oxygen affinity decreased with decrease in adult body size, standard P50 (at 36 C) varying from 24.6 torr in the largest (Red Kangaroo) to 41.9 torr in the smallest (Brown Marsupial Mouse). The relationship between P50 and body size is similar to the relationship which has been described previously for eutherian mammals. The Bohr factor (--deltalog P50/deltapH) and value for Hill n were generally in the range found for other land-dwelling mammals. All species had 2,3-DPG in their erythrocytes acting as a regulator of oxygen affinity. The polymorphism at position beta 2 in hemoglobin of the Grey Kangaroo was shown to affect the respiratory properties of the molecule. When beta 2 = histidine, which has a positively charged side chain, erythrocyte 2,3-DPG was higher, and P50 was higher, than when beta 2 = glutamine which has a neutral side chain.
已对七种澳大利亚有袋动物的血液进行了氧运输和2,3 - 二磷酸甘油酸（2,3 - DPG）水平的测量，这些动物的体重从35千克到0.03千克不等。它们分别是红袋鼠、灰袋鼠、岩大袋鼠、帚尾袋貂、长吻袋貂、赤褐袋鼩和褐袋鼩。氧亲和力随着成年动物体型的减小而降低，标准P50（36摄氏度时）从最大的（红袋鼠）24.6托变化到最小的（褐袋鼩）41.9托。P50与体型之间的关系类似于先前描述的真兽类哺乳动物的关系。玻尔因子（–Δlog P50/ΔpH）和希尔n值通常在其他陆生哺乳动物的范围内。所有物种的红细胞中都有2,3 - DPG作为氧亲和力的调节剂。已表明灰袋鼠血红蛋白β2位点的多态性会影响分子的呼吸特性。当β2 = 组氨酸（其侧链带正电荷）时，红细胞2,3 - DPG含量较高，P50也较高；而当β2 = 谷氨酰胺（其侧链呈中性）时则相反。
