The Hypoxia Adaptation Of The Cardiovascular System In Gansu Zokors (Myospalax Cansus)

As an emergency factor hypoxia affects many physical functions, especially in cardiovascular system. The adaptation mechanism of animals living in such low oxygen environment is even noticeable. Owning to adapt for higher CO₂ and lower O₂ of subterranean environment, all functions of Gansu zokors (Myospalax cansus) have been changed such as the cardiovascular system. This provides an ideal animal model for the study on the hypoxia adaptation mechanism. We adopt physiological and histological method to measure changes in physiological function and histological structure and to explore the mechanism of hypoxia adaptation in cardiovascular system of Gansu zokors. The results are as follows:1. In the Gansu zokor, the density of red blood cell is (8.31±0.70)×1012/L, (148.33±12.50)g/L for hemoglobin concentration and (0.46±0.03)L/L for hematocrit. The number of red blood cell (RBC), hemoglobin concentration (HGB) and hematocrit (HCT) are significantly higher after hypoxia adaptation in the Gansu zokor;however, its mean corpuscular volume (MCV), mean corpuscular hemoglobin (MCH) and mean corpuscular hemoglobin concentration (MCHC) decrease after hypoxia adaptation. The high RBC, HGB and HCT as well as lower MCV, MCH and MCHC in Gansu zokors are a possible approach to adapt the hypoxia environment.2. The systolic functional parameters such as LVSP, mCAP and the weight of right and left ventricle of intermittent hypoxia rats is increased significantly compared with normoxic control rats, while the diastole functional parameter -dp/dtmax was increased a little. These results suggest that Gansu zokors were adapted the hypoxic habitats (underground caves) and its cardiac compensations have been greatly developed, which can alleviate the hypoxia effects on the cardiac system.3. A high myoglobin level in myocardial cell of Gansu zokors is observed. As a result of the tissue is able to store oxygen by Mb. It also helps oxygen disperse to cells and provides oxygen for mitochondria. All these improve dispersion of oxygen in tissue. It is a mechanism that acts as a compensation and improves the lack of oxygen during sustaining hypoxia in heart.4. Myocardium ultra structure shows glycogenosomes are abundant in cell. Owingto this, Gansu zokors don't exibit hypoxia unwell symptom when mitochondria are destroyed in hypoxia environment. Under hypoxia environment Gansu zokors can maintain their energy supply by the changes of mitochondria or by the function of glycolysis.5. The Gansu zokor is well adapted for hypoxia. Cardiovascular system improves the capability of hypoxia adaptation by improving the function of blood, enhancing cardiac reserve and myocardial contractive. The capability of taking and using oxygen is improved as well. All these bring physiologic adaptation of hypoxia. Its capability is stronger than Sprague-Dawley. So it is an ideal animal model for researching physiological mechanism of hypoxia adaptation.In brief, the Gansu zokor is adapted to hypoxia habitats (underground caves) and organism maintains the stable internal environment by different responses in the individual, organs and cells. Its cardiac compensations have been greatly developed by improving the function of blood and the capability of taking and using oxygen, enhancing cardiac reserve, increasing myocardial contractive. Putting together the facts mentioned above, it can alleviate the hypoxia effects on cardiac functions. That is why the Gansu zokor is well fit to hypoxia environment.