College of Animal Science & Technology, Gansu Agricultural University, Lanzhou, P.R. China.
State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, P.R. China.
Vet Med Sci. 2022 Jan;8(1):177-186. doi: 10.1002/vms3.639. Epub 2021 Sep 25.
Tibetan pigs have exhibited unique characteristics from low-altitudes pigs and adapted well to the Qinghai-Tibet Plateau.
The current study was undertaken to investigate the hypoxic adaptation of heart in Tibetan pigs.
The hearts of Tibetan pigs and Landrace pigs raised at high or low altitudes were compared using 3D casting technology, scanning electron microscopy and real-time quantitative PCR (qRT-PCR).
We found that the ratio of the major axis to the minor axis and the density of the heart were significantly higher in Tibetan pigs than in Landrace pigs (p < 0.05). Tibetan pigs had larger diameters and higher densities of arterioles than Landrace pigs (p < 0.05), and these features have a similar variation with the expression of vascular endothelial growth factor (VEGF). The cardiac expression levels of hypoxia-inducible factor-1α (HIF-1α) and endothelial nitric oxide synthase (eNOS) were significantly higher in pigs reared at high altitudes than in those reared at low altitudes (p < 0.05). In contrast, Egl nine homolog 1 (EGLN1) had the opposite trend with respect to HIF-1α and eNOS and was related to red blood cell (RBC) counts. Notably, the expressions of erythropoietin (EPO) and endothelial PAS domain-containing protein 1 (EPAS1) were significantly higher in Landrace pigs kept at high altitudes than in the others (p < 0.05) and were associated with haemoglobin.
These findings show that the regulation of the heart function of Tibetan pigs in a hypoxic environment is manifested at various levels to ensure the circulation of blood under extreme environmental conditions.
藏猪具有不同于低海拔猪种的独特特性，能够很好地适应青藏高原环境。
本研究旨在探讨藏猪心脏的低氧适应机制。
采用 3D 铸造技术、扫描电镜和实时定量 PCR（qRT-PCR）比较了高原和低海拔饲养的藏猪和长白猪的心脏。
我们发现，藏猪心脏的长轴与短轴的比值和心脏密度均显著高于长白猪（p<0.05）。藏猪的小动脉直径和密度均大于长白猪（p<0.05），且这些特征与血管内皮生长因子（VEGF）的表达具有相似的变化趋势。高海拔饲养的猪心脏中缺氧诱导因子-1α（HIF-1α）和内皮型一氧化氮合酶（eNOS）的表达水平显著高于低海拔饲养的猪（p<0.05）。相反，Egl nine 同源物 1（EGLN1）与 HIF-1α和 eNOS 的趋势相反，与红细胞（RBC）计数有关。值得注意的是，高海拔饲养的长白猪中促红细胞生成素（EPO）和内皮 PAS 结构域蛋白 1（EPAS1）的表达显著高于其他组（p<0.05），与血红蛋白有关。
这些发现表明，藏猪在低氧环境下通过多个层面调节心脏功能，以确保在极端环境条件下的血液循环。
