Comparative Study Of Anoxia Tolerance In FMMU AlbinoGuinea-pigs And Pigment Guinea-pigs

Objective: Compare the anoxia tolerance between FMMU albino guinea-pigs and pigment guinea-pigs, and investigate the difference of anoxia tolerance between FMMU albino guinea-pigs and pigment guinea-pigs. Methods: 40 adult FMMU albino guinea-pigs and 40 adult pigment guinea-pigs were equally divided into four groups: 1) normal control group; 2) chronic hypoxic 7d group; 3) chronic hypoxic 14d group; 4) chronic hypoxic 21d group. The hypoxic groups were placed in normal pressure hypoxia self-made chamber, The hemoglobin concentration Pa02 - PaCO2 and erythrocyte number were determined in FMMU guinea-pigs and pigment guinea-pigs anesthetized after exposed to hypoxia. The change of activity of NAD-COQ and Cytochrome oxidase in myocardial mitochondria were observed with clark oxygen electrode and biochemical method. The right lung and right heart were removed and placed in 10% Formalin, and the change of ultrastructure of myocardial and pulmonary alveolus was observed through electron microscope. Comparing the death rate of FMMU albino guinea-pigs and pigment guinea-pigs under ultimate hypoxia. Results: 1. The concentration of hemoglobin (Ilb) ,the number of erythrocyte significantly increase in FMMU albino guinea-pigs and pigment guinea-pigs after exposed to hypoxia, Hb of FMMU albino guinea-pigs was higher than that of pigment guinea-pigs (25.45 ?.96 vs. 23.03 ?.68). 2. The ultrastructure of pulmonary alveolus has changed both in FMMU albino guinea-pigs and pigment guinea-pigs. The number of osmiophilic multilamellar bodies reduced in type II alveolar. The membrane of Type I alveolar cells become thinner or rupture, the surface of alveolar cells present exiguous salience containing narrow, or occlusion capillaries. The capillaries in alveolar septum become broaden or narrow or occlusion, it proved that the alveolar epithelium and capillary permeability increase under normal pressure hypoxia condition. 3. Hypoxia induced the swell of myocardial mitochondria in FMMU albino guinea-pigs and pigment guinea-pigs. The permeability of membrane in myocardial mitochondria increases. The activity of NAD + ?COQ decrease significantly after exposed to hypoxia 7d, and rise gradually following the prolong of hypoxia, but the activity of NAD~ ?COQ lower than that of control group; The activity of Cytochrome oxidase rise, the activity of Cytochrome oxidase of FMMU albino guinea-pigs is significantly higher than that of pigment guinea-pigs (2824.23?14.76 vs. 2666.79?91.68), the activity of Cytochrome oxidase rise the highest after exposed to hypoxia l4d; The oxygen-consumption of JV state of myocardial mitochondria both in FMMU albino guinea-pigs and pigment guinea-pigs are higher than that of control groups respectively {(47.48 ? 1.97 vs. 36.49 ?2.41) (57.41 ?2.68 vs. 38.53 ?1.74)} after exposed hypoxia, there are significantly difference between FMMU albino guinea-pigs and pigment guinea-pigs (47.48 ?1.97 vs. 57.41 ?2.68) after exposed to hypoxia 7d. PlO rise obviously at the beginning of hypoxia, with the prolong of hypoxia PlO decrease in FMMU albino guinea-pigs and pigment guinea-pigs. 4.The death rate of pigment guinea-pigs reaches 50 percents when the oxygen density decrease to 7.5 percents under ultimate hypoxia, while the oxygen density decrease to 5 percents when death rate of FMMU guinea-pigs reaches 50 percents. All of the pigment guin...