Basic principle: D-galactose is continuously injected into animals within a certain period of time to increase the concentration of galactose in cells in the body. It is reduced to galactitol by the catalysis of aldose reductase. The substance will not be further metabolized and accumulated by cells. It will affect the normal osmotic pressure inside the cell, leading to swelling, dysfunction, metabolic disorders, damage and exhaustion of the body's antioxidant defense system and accumulation of free radicals. At the same time, when galactose is reduced to galactitol, which destroys lipids in cell membranes, increases lipid peroxides and lipid fusion factors and causes senescence, (O2-) is produced.
Steps:
Take a healthy female mouse and feed it with a normal diet. The mice in the model group were injected with D-galactose (0.25 ml/10 g) subcutaneously at the back of the neck every day. After 6-8 weeks, the mice moved slowly, their coat was gray, their body was thin and it was obviously showing signs of aging, and A subacute aging model is provided. In the blank control group, normal saline (0.25 ml/10 g) was injected subcutaneously every day. Two hours after the last administration and D-galactose, a learning and memory training experiment (avoid dark experiment) was carried out, the memory score was measured the next day, and blood was collected from the orbit and sacrificed. The tissues of mouse thymus, spleen, brain, liver and heart were taken to determine various indicators of aging.
Straight-through test: The reflector box is divided into 5 separate boxes, each box is 36 cm x 12 cm x 12 cm, with 2 separate light and dark rooms. The bright room is made of transparent plexiglass. At the bottom of the darkroom is a copper grid that can carry 36V current. There is a 3 cm diameter hole between the bright and dark room. The reflection box is connected to the microcomputer by a cable. The computer controls the record of animals entering a bright room through a hole. Latent period in a dark room. During the experiment, place the mouse in a bright room with its face facing away from the hole and start timing at the same time. Take out the mouse and record the latency of the mouse from the bright room to the dark room and the number of electric shocks within 5 minutes. This is the result of training. Test your score after 24 hours.
Measurement index:
1, weight
2, organ index (thymus, spleen, liver, brain organ index)
Organ Index=Organ weight/body weight x 100%
3, antioxidant index
Blood: MDA, SOD, MAO
Liver and brain: MDA
Brain: MAO
Note:
1. Choose a female mouse. Due to the long experiment time, male mice live in groups for a long time and are easy to chew. It will cause harm and affect the results of the experiment.
2. Injection and administration must be sterile. The bedding and drinking water bottle in the squirrel cage should be replaced regularly and cleaned to keep it clean. As it takes time, the body gradually ages and its functional status gradually deteriorates.