| Plateau pika(Ochotona curzoniae)is an indigenous animal on the Qinghai-Tibet Plateau.It has evolved a unique and highly efficient energy metabolism system and oxygen utilization mechanism in the alpine and low-oxygen environment.Currently,it is considered that the plateau pika is a representative animal completely adapted to the plateau hypoxia and is one of the animal models for the study of hypoxia adaptation.We studied the changes of red blood cell number,red blood cell specific volume,hemoglobin,respiratory metabolism and related hormones in serum between SD rats and plateau pika under hypoxic conditions by comparing them under simulated hypoxic conditions.(1)Compared with the control group,under 5% and 10% hypoxic conditions,the oxygen consumption,carbon dioxide production and energy consumption of plateau pikas and SD rats are extremely significantly reduced(P(27)0.01),The metabolism of the animal body slows down,the food intake of plateau pikas and SD rats decreases,and the weight gain decreases(P(27)0.01),and it also significantly decreases with the decrease of oxygen content(P(27)0.01).(2)Under hypoxic conditions,the number of red blood cells,hematocrit and hemoglobin content in the blood of plateau pikas and SD rats all increased significantly(P(27)0.01),which was negatively correlated with the oxygen content in the environment Sex.Compared with SD rats,plateau pikas have increased hematocrit,red blood cell number and hemoglobin content.(3)Under hypoxic conditions,erythropoietin in the serum of pikas and SD rats increased significantly(P(27)0.01),and SD rats under hypoxic conditions changed more significantly than plateau pikas(P(27)0.01).Especially in a 5% hypoxic environment,the content of erythropoietin in the serum of SD rats on the 14 th day can be significantly increased(P(27)0.01).The above results indicate that plateau pikas are more adaptable to hypoxia than SD rats.(4)In a hypoxic environment,the content of triiodothyroxine,antidiuretic hormone and testosterone in the serum of plateau pikas and SD rats is extremely significantly reduced(P(27)0.01);the content of estradiol in the serum of plateau pikas increases high,no statistical significance at the 14 th day(P(27)0.05),the content of estradiol in the serum of SD rats decreased significantly at the 14 th day(P(27)0.01).(5)At 1d in a 10% hypoxic environment,liver glycogen in the liver tissue of SD rats accumulated,and it was extremely significantly reduced at 14d(P(27)0.01),and in a 5% hypoxic environment,the liver Glycogen accumulation was not significant;glycogen in the liver tissue of plateau pikas did not accumulate under simulated hypoxic conditions,and decreased extremely significantly at 14 days with time(P(27)0.01).In 5% and 10% oxygen environments,the content of myocardial glycogen in plateau pikas and SD rats decreased significantly at 14 days(P(27)0.01).(6)In the hypoxic environment simulated at altitudes of 5 000 m and 6 000 m,the number of red blood cells,hematocrit,hemoglobin and erythropoietin content in the blood of SD rats increased significantly(P(27)0.01),It is positively correlated with altitude;serum estradiol,triiodothyroxine and antidiuretic hormone content are extremely significantly reduced(P(27)0.01),while testosterone content increases in a hypoxic environment of 5000 m(P(27)0.05)),it can be significantly reduced by the 14 th day of hypoxia(P(27)0.01);the accumulation of liver glycogen content in liver tissue is not statistically significant(P(27)0.05),and both liver glycogen and myocardial glycogen are both It showed a very significant decrease(P(27)0.01).The above results are consistent with the change trend of SD rats in normal pressure and hypoxia environment.(7)In a hypoxic environment with a simulated altitude of 5 000 m,the mean arterial pressure of SD rats rose to the highest at 2d(P(27)0.01),and it increased significantly at 14d(P(27)0.05);heart rate was at 2d It began to decrease after 14 days,and it was not statistically significant at 14 days(P(27)0.05);in a hypoxic environment at a simulated altitude of 6 000 m,the mean arterial pressure and heart rate of SD rats increased significantly within 2 days(P(27)0.01);Lung tissue in a hypoxic environment darkens in color,becomes less elastic,gradually narrows the alveolar cavity,thickens and structurally disordered alveolar walls,and has obvious inflammatory cell infiltration,accompanied by congestion.This shows that:(1)Whether it is a mountain animal or a plain animal,the secretion of erythropoietin increases after entering the mountain environment,which promotes the synthesis of animal hemoglobin.The plateau pika has a low hematocrit and a large number of red blood cells per unit volume of plasma,indicating that the plateau pika can better adapt to the hypoxic environment.(2)Plateau pika and SD rats under high altitude hypoxic environment will reduce the energy metabolism of the animal body.At the same time,under the same hypoxic condition,the changes of the plateau pika's food intake,weight and respiratory metabolism are all smaller than SD Rats indicate that the oxygen acquisition capacity and oxygen utilization capacity of plateau pikas under hypoxic conditions are stronger than that of SD rats.(3)Hypoxia can inhibit the secretion of hormones in the hypothalamic-pituitary system of plateau pikas and SD rats,which may be related to the time and degree of hypoxia.(4)Through a comparative study of female and male animals,it is found that male SD rats are more sensitive to hypoxia than female SD rats,while for plateau pikas,the difference between female and male rats in simulated hypoxic environment is smaller. |
PDF Full Text Request