Benga Gheorghe, Chapman Bogdan E, Romeo Tony, Cox Guy C, Kuchel Philip W
Laboratory of Genetic Explorations, Cluj County Clinical Emergency Hospital, 6 Pasteur St., 400349, Cluj-Napoca, Romania,
Protoplasma. 2015 Jul;252(4):1181-5. doi: 10.1007/s00709-014-0747-4. Epub 2014 Dec 23.
The morphology and diffusional water permeability (P d) of red blood cells (RBCs) from green sea turtle (GST) (Chelonia mydas) are presented for the first time. The RBCs had an ellipsoidal shape with full-axis lengths (diameters): D = 14.4 μm; d = 10.2 μm; h = 2.8 μm. The values of P d (cm s(-1)) were 5.1 × 10(-3) at 15 °C, 5.7 × 10(-3) at 20 °C, 6.3 × 10(-3) at 25 °C, 6.8 × 10(-3) at 30 °C, and 7.9 × 10(-3) at 37 °C (i.e., significantly higher than in human RBCs in which it was measured to be 4.2 × 10(-3) at 25 °C, 5.0 × 10(-3) at 30 °C, and 6.2 × 10(-3) at 37 °C). There was a lack of inhibition of P d of GST RBCs by p-chloromercuribenzoate (PCMB), a well-known inhibitor of the RBC water channel proteins (WCPs). The activation energy of water diffusion (E a,d) in GST RBCs was 15.0 ± 1.6 kJ mol(-1) which is lower than the E a,d for human RBCs (~25 kJ mol(-1)). These results indicate that in the membrane of GST RBCs, there were no WCPs that were inhibited by the mercurial reagent, while the lipid bilayer of this membrane is unusually permeable to water. This is likely to be a phylogenetically old trait, like that found in amphibians and even the later birds, all of which have nucleated erythrocytes; and it is also likely to be a result of the animal's adaptation to a herbivorous diet (algae and seagrasses).
首次呈现了绿海龟（GST，蠵龟）红细胞（RBC）的形态和扩散水渗透率（Pd）。红细胞呈椭圆形，全轴长度（直径）：D = 14.4μm；d = 10.2μm；h = 2.8μm。Pd（cm s(-1)）的值在15°C时为5.1×10(-3)，20°C时为5.7×10(-3)，25°C时为6.3×10(-3)，30°C时为6.8×10(-3)，37°C时为7.9×10(-3)（即显著高于人类红细胞，人类红细胞在25°C时测得为4.2×10(-3)，30°C时为5.0×10(-3)，37°C时为6.2×10(-3)）。对红细胞水通道蛋白（WCPs）的著名抑制剂对氯汞苯甲酸（PCMB）对GST红细胞的Pd没有抑制作用。GST红细胞中水扩散的活化能（Ea,d）为15.0±1.6 kJ mol(-1)，低于人类红细胞的Ea,d（约25 kJ mol(-1)）。这些结果表明，在GST红细胞膜中，不存在被汞试剂抑制的WCPs，而该膜的脂质双层对水具有异常高的渗透性。这可能是一种系统发育上古老的特征，类似于在两栖动物甚至后来的鸟类中发现的特征，它们都有有核红细胞；这也可能是该动物适应草食性饮食（藻类和海草）的结果。
