Experimental Study On Impact On The Morphology Of Rat Liver Tissue Structures And Activity Of Antioxidant Enzymes After Stopping Training

I stop the rats'training, after taking a great load exercises for a certain period, purpose of this essay is to observe variation and antioxidant enzyme activities of liver structures and provide experimental evidence to ensure that whether exercises could cause structure variation and adaptation changes of antioxidant enzyme activities of livers after stopping training.54 two-month-old inbred male Wistar rats are chosen as samples and divided them into normal group and training group randomly via their weights. Rats in normal group only served food freely without any forms of exercises. While rats in training group should swim in a great load for seven weeks in a big plastic barrel. Then eight rats of each group should be chosen randomly and killed, others in training group are fed in the normal way after stopping training . Stop training group is divided into a four -week and a six-week group and the rats are fed normally. Rats in training group are chosen according to 24 hours after the last exercises and comparison and stop training groups follow the same way.Experimental Results:1. Weights of rats in training group increase slowly than the comparison group, and the difference is huge. Serum CK of the rats increase obviously in training group and MDA also goes up without great difference. It shows that this establishment of rats exercising model of motorial fatigue is successful.2. Protein content in liver tissues of rats increase much more than the ones in comparison group while GPX and SOD activities declines obviously after 7-week training with great load. MDA of rats in training group goes up slowly and the difference is not adequate.Stopping training for four weeks, GPX activities of rats tissues in training group decline slowly, but stop exercising for six weeks the difference is obvious. Changes of SOD is weaker than GPX, it recovers to a lower level after stopping training for four weeks and the gap is big compared with rats in comparison group, while activities after stopping training for four weeks and six weeks are the same. MDA also does the same thing.3. All detect indexes of rats'liver tissues in comparison group have not obvious differences and it shows the experimental result is reliable. Differences of protein contents of three times in training group are not obvious, either. Activity of GPX has great difference between four-week training group and seven-week training group, the difference is not obvious between six-week and seven-week training groups, while compared with four-week training group, GPX activity declines. SOD among the three groups has not obvious differences. MDA of rats'liver tissues in four-week and six-week training groups is reducing sharply compared with seven-week training group.4. Liver structures damage strongly in training group compared with comparison group, HE biopsy indicates that sinusoid becomes narrowly and even disappears, arrangement of hepatic cord is disordered, portal areas in interlobular and lobular vessels expanding moderately. The changes recover gradually after stopping training for four weeks. The same changes are available after stopping exercising for six weeks.Electron microscopy shows that nuclear membrane of liver cells are winding slightly, nuclear chromatin is agglutinating lightly, mitochondria is swelling and electron density is being low. Lipid droplets are increasing compared with comparison group. Surface microvilli of liver cells of Disse decrease. After four weeks without training, liver cells structures improved a lot and its organelles are abundant and in good shapes. The same thing occurs in liver structures, its cell nucleolus can be seen easily and nuclear chromosomes are well-distributed. Organelles are abundant, mitochondria's structures are integral and clear and endoplasmic reticulum of cytoplasm is expanding slightly.Conclusions:1. Heavy load training can cause fatigue in rats, large amounts of free radicals appear in liver tissues, meanwhile, free radical metabolism, which can trigger increase of adaptation of activity of antioxidant enzymes, in liver tissues are promoted. GPX has stronger adaptation than SOD. This adaptation could disappear after stopping training.2. Heavy load training can cause change of liver structures of rats and some small injuries also occur. All the injuries could recovers itself. The experiment proves that fatigue-induced liver injury can recover itself, it further proves the science of training theory.