ã€Abstract】Objective To observe the changes of microscopic and ultrastructural changes of body weight and gastrocnemius muscle during hypoxia and hypoxia combined exercise in order to investigate the effect of proper exercise on skeletal muscle under hypoxia. Methods The hypoxic and hypoxic complex exercise model of rats was established. The microscopic and ultrastructural changes of rat gastrocnemius muscle were observed by light microscopy and transmission electron microscopy. Results There was a significant difference in body weight between the hypoxic-quiet group in the hypoxic-complex exercise group (). The skeletal muscle structure of the hypoxic complex exercise group was normal. The number of mitochondria increased, and the skeletal muscle fibers increased the capillary proliferation. Conclusion Hypoxic combined with proper exercise can maintain the normal shape of skeletal muscle. Enhance the aerobic metabolism of skeletal muscle to protect skeletal muscle, thereby improving the hypoxic adaptation ability of skeletal muscle and promoting hypoxia. [Keywords] hypoxia exercise skeletal muscle microstructure ultrastructure for the first time into the plateau hypoxia area, due to overall or local hypoxia will cause a series of reactions in the body, such as acute altitude sickness. How to minimize the altitude sickness and improve the labor and training ability of those who enter the plateau is an important topic in plateau medical research. Studies have shown that proper physical exercise can promote high altitude exercise, which is characterized by enhancing heart and lung function, improving the body's oxygen uptake, transportation and utilization, and improving the body's maximum oxygen consumption capacity. In this study, the effects of proper exercise on skeletal muscle under hypoxia were investigated by observing the changes of microscopic and ultrastructural changes of body weight and gastrocnemius muscle during hypoxia and hypoxia combined exercise. Materials and Methods First, the experimental materials Animals and groupings: () Male rats were only provided by the Experimental Animal Center of Southern Medical University, age, body weight. They were randomly divided into four groups: group, normal oxygen quiet group (only); group, normal oxygen exercise group (only); group, hypoxic quiet group (only); group, hypoxic exercise group (only). Main reagents and instruments: atmospheric pressure hypoxic tent system (US company), two types of electric animal running platform (Hangzhou Litai Technology Co., Ltd.), transmission electron microscope (Japan Electronics), electronic balance (). Second, the experimental method Animal model: using a normal-pressure hypoxic tent system to simulate oxygen content (equivalent to altitude), of which two groups of animals Every day: : Put in a hypoxic tent. Two types of experimental electric animal running platforms, which can automatically record the training time of rats. The distance between the exercise and the running speed is equipped with light, electricity and sound stimulation devices. The two groups of rats are trained on the treadmill every day, and the running speed is set to . Group rats were housed under normal conditions without any treatment factors. Material: randomly selected from each group of animals on the first, the day after the start of the experiment, weighing, dialysis of chloral hydrate solution in the peritoneal cavity drunk. The left gastrocnemius muscle was quickly and completely removed. Preparation of light microscopy sections: The left and right skeletal muscle tissue blocks were fixed by formalin and embedded in conventional paraffin. The sections were conventionally dewaxed with xylene and washed with various stages of ethanol to water: xylene ( ) xylene ethanol distilled water. Hematoxylin staining, tap water washing. Hydrochloric acid differentiation (lifting number). Tap water dip Bubble. Set the red liquid. Conventional dehydration, mounting: xylene neutral resin is sealed. Preparation of ultrathin sections of electron microscopy: A few of the above skeletal muscle tissues were used to prepare ultrathin sections of electron microscopy. Sharp eye scissors cut the specimen into left and right skeletal muscle tissue blocks. The muscle tissue was fixed in a vial containing a special TEM solution for glutaraldehyde. Wash with buffer. Tannic acid After fixing. Conventional electron microscope sample preparation procedures for dehydration, infiltration, embedding, ultrathin sectioning, and uranium lead staining. Observation by transmission electron microscopy. Third, statistical analysis The application software tests each set of results and the results are expressed. The difference is significant. Result Rat body weight: It can be seen from the table that with the increase of time, the body weight of each group has significant difference with time; the weight loss of rats in hypoxic quiet group is significantly different from other groups, chronic low Oxygen is especially noticeable. Exercise can promote weight gain in rats, and even counteract the weight loss caused by hypoxia, and this change exceeds the increase in natural body weight of rats in the normoxia group, which is slightly reduced compared with the normotensive exercise group of the same exercise volume. But the difference is not significant. Proper exercise under hypoxic conditions can increase the body's ability to subdue hypoxia. Discuss The main factor affecting the human body in the high altitude environment is hypoxia. After the plain people enter the plateau, the body undergoes a series of compensatory adaptive changes under the regulation of neurohumoral fluid to adapt to the plateau environment. This process is called submission. Due to individual differences, each person's ability to learn is different. After most plain people enter the plateau, they can obtain good habits of the plateau environment through the compensatory adaptive response of the body, and can work and live normally in the plateau environment without any discomfort. But there are also some people from the plains After entering the plateau, due to insufficient or too strong compensatory adaptive response, poor habits occur, resulting in various acute and chronic altitude sickness. How to improve the low-oxygen adaptability of workers and the level of high-level health care, improve the combat capability of the plateau troops and the training results of athletes, and effective intervention of hypoxia is of great significance to human damage. Maintaining the normal structure and function of skeletal muscle plays an important role in improving the working capacity of the plateau. The results of this experiment showed that under the condition of hypoxia, the rats showed various incompatibility phenomena such as weight loss, obvious shrinkage of muscle fibers, increased mitochondrial volume of skeletal muscle in acute phase, slight swelling of sputum, enlargement of sacral cavity, disorder of sputum, Golgi. The body and endoplasmic reticulum are slightly enlarged, and the formation of blood vessels can shorten the distance of oxygen diffusion from capillaries to tissue cells. Improving the oxygen supply of tissues is one of the important mechanisms for the body to be hypoxic at the local tissue level. Under simple hypoxic conditions, skeletal muscle fibers are obviously atrophied, which has certain compensatory adaptation significance for the body under hypoxic conditions to reduce local oxygen consumption and maintain energy metabolism of major organs. Skeletal muscle atrophy may be associated with a decrease in oxygen supply to skeletal muscle during hypoxia, a decrease in anabolism, and a functional "disuse" due to reduced animal activity during hypoxia. The skeletal muscle capillary proliferation in hypoxia alone has been controversial. Early studies have found that animals living in a high altitude environment have increased capillary density and are inferred to have capillary proliferation. However, the increase in skeletal muscle capillary density during hypoxia is due to atrophy of skeletal muscle fibers. This view was confirmed by some subsequent experiments. The vascular density is increased but the ratio of the number of capillaries per unit area to the number of muscle fibers is unchanged due to the atrophy of skeletal muscle fibers. It shows that there is no significant increase in the number of capillaries under low oxygen and quiet conditions. However, due to the atrophy of the muscle fibers and the increase in the density of the capillaries, the diffusion distance of oxygen is shortened, which is beneficial to the supply of oxygen in the skeletal muscle tissue. This may be characterized by the adaptation of skeletal muscle tissue to hypoxic acclimatization during hypoxia. Hypoxia combined with proper exercise The skeletal muscle fibers do not shrink and new capillaries appear to accommodate the enhancement of skeletal muscle function. The imbalance of supply and demand ratio of skeletal muscle oxygen in the early stage of hypoxic complex exercise may be the basis for skeletal muscle capillary proliferation. When hypoxia is quiet, the increase in the number of red blood cells leads to a decrease in the activity of the oxygen supply and the shrinkage of the muscle fibers, so that the oxygen demand of the skeletal muscles is relatively reduced, so that the imbalance of supply and demand of oxygen is not obvious, so the capillaries do not proliferate. Studies have shown that the expression of vascular endothelial growth factor (VEGF) is significantly increased in hypoxic combined with moderately exercised rat skeletal muscle capillaries, and there is no significant change in the amount of skeletal muscle capillaries in hypoxic quiet rats. . The mechanism of hypoxic complex exercise-induced capillary proliferation of skeletal muscle may be related to the increased expression of hypoxia-inducible factor (VEGF) during hypoxia combined exercise. As a regulated transcription factor, expression in tissues is regulated directly from the gene level. It can increase the permeability of blood vessels, especially tiny blood vessels, and make extravasation of plasma macromolecules. By binding to specific receptors on the surface of vascular endothelial cells, it can significantly promote the growth of fibroblasts and vascular endothelial cells, synthesize and secrete extracellular matrix such as collagen, and strongly promote the formation of new blood vessels. It is adapted to physiological conditions and pathophysiology. The main regulator of blood vessel growth in the process. Hypoxic complex exercise can increase the expression in the tissue by increasing the expression To promote the formation of new blood vessels. In summary, we believe that hypoxia combined with proper exercise can maintain the normal weight of the body, stabilize the normal structure of skeletal muscle, increase the number of mitochondria, inhibit skeletal muscle atrophy and promote skeletal muscle capillary angiogenesis to improve the blood supply of skeletal muscle. The aerobic metabolism of skeletal muscle promotes the body's acceptance of the low-oxygen environment in the plateau. Shenzhen Fuvision Electronics Co., Ltd. , https://www.outdoorsolarcameras.com
Experimental study on morphological changes of rat skeletal muscle induced by hypoxia and exercise
Next Article
Not everyone can eat peaches