Protective Effect of Modified Hemoglobin on Rabbits and Goats in High-Altitude Sickness.

The prevalence and severity of high-altitude sickness increases with increasing altitude. Prevention of hypoxia caused by high-altitude sickness is an urgent problem. As a novel oxygen-carrying fluid, modified hemoglobin can carry oxygen in a full oxygen partial pressure environment and release oxygen in a low oxygen partial pressure environment. It is unclear whether modified hemoglobin can improve hypoxic injury on a plateau. Using hypobaric chamber rabbit (5000 m) and plateau goat (3600 m) models, general behavioral scores and vital signs, hemodynamic, vital organ functions, and blood gas are measured. The results show that the general behavioral scores and vital signs decrease significantly in the hypobaric chamber or plateau, and the modified hemoglobin can effectively improve the general behavioral scores and vital signs in rabbits and goats, and reduce the degree of damage to vital organs. Further studies reveal that arterial partial pressure of oxygen (PaO2 ) and arterial oxygen saturation (SaO2 ) on the plateau decrease rapidly, and the modified hemoglobin could increase PaO2 and SaO2 ; thus, increasing the oxygen-carrying capacity. Moreover, modified hemoglobin has few side effects on hemodynamics and kidney injury. These results indicate that modified hemoglobin has a protective effect against high-altitude sickness.

The Protective Effect of a Novel Cross-Linked Hemoglobin-Based Oxygen Carrier on Hypoxia Injury of Acute Mountain Sickness in Rabbits and Goats.

Hypoxia is the major cause of acute altitude hypoxia injury in acute mountain sickness (AMS). YQ23 is a kind of novel bovine-derived, cross-linked hemoglobin-based oxygen carrier (HBOC). It has an excellent capacity for carrying and releasing oxygen. Whether YQ23 has a protective effect on the acute altitude hypoxia injury in AMS is unclear. In investigating this mechanism, the hypobaric chamber rabbit model and plain-to-plateau goat model were used. Furthermore, this study measured the effects of YQ23 on the ability of general behavior, general vital signs, Electrocardiograph (ECG), hemodynamics, vital organ injury markers, and blood gases in hypobaric chamber rabbits and plain-to-plateau goats. Our results showed that the ability of general behavior (general behavioral scores, GBS) (GBS: 18 ± 0.0 vs. 14 ± 0.5, p < 0.01) and the general vital signs weakened [Heart rate (HR, beats/min): 253.5 ± 8.7 vs. 301.1 ± 19.8, p < 0.01; Respiratory rate (RR, breaths/min): 86.1 ± 5.2 vs. 101.2 ± 7.2, p < 0.01] after exposure to plateau environment. YQ23 treatment significantly improved the ability of general behavior (GBS: 15.8 ± 0.5 vs. 14.0 ± 0.5, p < 0.01) and general vital signs [HR (beats/min): 237.8 ± 24.6 vs. 301.1 ± 19.8, p < 0.01; RR (breaths/min): 86.9 ± 6.6 vs. 101.2 ± 7.2, p < 0.01]. The level of blood PaO2 (mmHg) (115.3 ± 4.7 vs. 64.2 ± 5.6, p < 0.01) and SaO2(%) (97.7 ± 0.7 vs. 65.8 ± 3.1, p < 0.01) sharply decreased after exposure to plateau, YQ23 treatment significantly improved the blood PaO2 (mmHg) (97.6 ± 3.7 vs. 64.2 ± 5.6, p < 0.01) and SaO2(%) (82.7 ± 5.2 vs. 65.8 ± 3.1, p < 0.01). The cardiac ischemia and injury marker was increased [troponin (TnT, µg/L):0.08 ± 0.01 vs. 0.12 ± 0.02, p < 0.01], as well as the renal [blood urea nitrogen (BUN, mmol/L): 6.0 ± 0.7 vs. 7.3 ± 0.5, p < 0.01] and liver injury marker [alanine aminotransferase (ALT, U/L): 45.8 ± 3.6 vs. 54.6 ± 4.2, p < 0.01] was increased after exposure to a plateau environment. YQ23 treatment markedly alleviated cardiac ischemia [TnT (µg/L):0.10 ± 0.01 vs 0.12 ± 0.02, p < 0.01] and mitigated the vital organ injury. Besides, YQ23 exhibited no adverse effects on hemodynamics, myocardial ischemia, and renal injury. In conclusion, YQ23 effectively alleviates acute altitude hypoxia injury of AMS without aside effects.