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Objective: To identify cardiac mechanisms that contribute to adaptation to high altitudes in Tibetan antelope (Pantholops hodgsonii)., Animals: 9 male Tibetan antelope and 10 male Tibetan sheep (Ovis aries)., Procedures: Tibetan antelope and Tibetan sheep inhabiting a region with an altitude of 4,300 m were captured, and several cardiac variables were measured. Expression of genes for atrial natriuretic peptide, brain natriuretic peptide, and calcium-calmodulin-dependent protein kinase II δ was measured via real-time PCR assay., Results: Ratios of heart weight to body weight for Tibetan antelope were significantly greater than those of Tibetan sheep, but ratios of right-left ventricular weights were similar. Mean ± SD baseline heart rate (26.33 ± 6.15 beats/min) and systolic arterial blood pressure (97.75 ± 9.56 mm Hg) of antelope were significantly lower than those of sheep (34.20 ± 6.57 beats/min and 130.06 ± 17.79 mm Hg, respectively). The maximum rate of rise in ventricular pressure in antelope was similar to that in Tibetan sheep, but after exposure to air providing a fraction of inspired oxygen of 14.6% or 12.5% (ie, hypoxic conditions), the maximum rate of rise in ventricular pressure of the antelope increased significantly to 145.1% or 148.1%, respectively, whereas that of the sheep decreased to 68.4% or 70.5%, respectively. Gene expression of calcium-calmodulin-dependent protein kinase II δ and atrial natriuretic peptide, but not brain natriuretic peptide, in the left ventricle of the heart was significantly higher in antelope than in sheep., Conclusions and Clinical Relevance: Hearts of the Tibetan antelope in this study were well adapted to high-altitude hypoxia as shown by higher heart weight ratios, cardiac contractility in hypoxic conditions, and expression of key genes regulating cardiac contractility and cardiac hypertrophy, compared with values for Tibetan sheep.

Aim: To clone and analyze the encoding region of alpha-globin gene from Tibetan antelope., Methods: Total RNA was isolated from an adolescent Tibetan antelope liver, and Tibetan antelope alpha-globin gene was amplified by RT-PCR. The PCR product was cloned into pGEM-T vector and sequenced. Nucleotide sequences were compared with GenBank data by Blast method., Results: The encoding region of alpha-globin gene of Tibetan antelope was obtained and deposited in GenBank as accession number DQ650713. Compared with sheep alpha-chain, alterations in important regions could be noted: a132 Asn-->Ser, a134 Ser-->Gly; but 19 differences were detected when compared with that of human. Phylogenetic analysis showed that the encoding region of alpha-globin gene of Tibetan antelope was most likely close to that of sheep and goat., Conclusion: The encoding region of gene Tibetan antelope alpha-globin gene is successfully cloned, which provides basic information for elucidating the possible role of hemoglobin in high altitude adaptation of Tibetan antelope.