| 99Tc-MDP (99Tc-methylenediphosphonate), is also called yunke, the main ingredients are high-Tc [TC] Sodium Injection (A agent), and stannous Methylene diphosphonate lyophilized product (B agents). 99Tc-MDP can eliminate free radicals, protect the activity of superoxide dismutase(SOD), inhibit the production of complex pathology, to prevent free radical damage to the body, through valence variation of trace elements. Subacute aging model induced by High-dose D-galactose is the most commonly method of preparing an animal model of aging. The model has a variety of aging characteristics: Short-lived, learning and memory disorders, nervous system degeneration, decreased immunity and fecundity. It is widely used in the mechanism of aging, the drug efficacy evaluation of anti-oxidants and anti-aging. VitE plays a part in anti-oxidative damage and immune defense. This study, we select VitE as the positive control group, make aging model with D-galactose to verify whether 99Tc-MDP has the effect of anti-aging.Objective: To observe the effect of 99Tc-MDP on aged–mice induced by D-galactose. We observed weight, behavior, brain section, thymus index, spleen index and measured SOD, MDA and GSH-PX content in the serum, liver, brain, heart and kidney tissue to determine whether 99Tc-MDP has anti-aging effect and find its possible mechanism for further study of 99Tc-MDP pharmacology effect. The experimental study may be provide the new theory and experiment instruction to the development of new anti-aging drug.Methods: 48 healthy female Kunming mice were randomly divided into 6 groups: normal control group, model group, vitamin E group, low, middle and high dosage group of 99Tc-MDP. Except the normal control group, the other mice were injected of 0.25ml/20g 10% D-galactose saline injection by subcutaneous of neck. The model group, vitamin E group, and 99Tc-MDP groups were injected with 0.25ml/20g 10%D-galactose for 42 days. At the same time, the 99Tc-MDP groups were injected various dosages of 99Tc-MDP respectively into abdominal cavity twice a day, and vitamin E group were given vitamin E by intragastric administration from the first day. Low, middle, high dosages of 99Tc-MDP group were respectively administrated 99Tc at 3.5×10-4μg99Tc/20g, 7.0×10-4μg99Tc/20g, 1.4×10-3μg 99Tc/20g by intraperitoneal injection. After behavioral testing, took the each mouse blood by removing the eye, centrifuged ( 15 min, 3000rpm) approximately 2 h later and 1.0 mL serum samples stored at–80℃. And then mice were killed by dislocation, took the thymus, spleen, brain, heart, liver, kidney, wash the blood stains with cold saline, dried the organs of surface water. The body weight, and the thymus index and spleen index of each mouse were observed〔organ index = organ weight(mg) / animal weight (g)〕.The part of brain were made of 10% brain tissue homogenate, stored at–80℃.Heart, liver, kidney, respectively were made of tissue homogenate with the same method. Fixed the remaining brain tissue with 10% formaldehyde, then paraffin-embedded, 5μm thick sections, baking overnight at 60℃to prepare for HE staining.Results: Six weeks later, the mice in the model group showed bending body, body weight loss, loose skin, murky gray and sparse hair, slow action.①Compared with the control group, the activities of SOD in model group'blood, were significantly decreased (P<0.01), that the aging model were created successfully. Compared with model group, VitE could significantly increase the activities of SOD (P<0.01), shows that the positive control group in this experiment has a control role.②The step down test shows that compared with normal group, the model group the incubation period shorten (P<0.01), the number of mistakes increased (P <0.01); Compared with model group, VitE group and three dosage of 99Tc-MDP groups could significantly prolong latency (P<0.01) and reduce the number of mistakes (P<0.01).③LASHLEY water maze test indicated that compared with normal group, the model group could prolong latency (P<0.01) and increase the number of mistakes (P<0.01); VitE group and three dosages of 99Tc-MDP groups could significantly shorten the incubation period(P<0.01)and reduce the number of mistakes (P<0.01).④Compared with the control group, the thymus and spleen atrophy in model group (P<0.01 or P<0.05); Compared with model group, the thymus index and spleen index were significantly increased in VitE group and three dosages of99Tc-MDP groups (P<0.01 or P<0.05).⑤The four physical and biochemistric index SOD, MDA, MAO, GSH-PX showed the 99Tc-MDP groups and VitE group increase the activities of SOD, GSH-PX (P<0.01 or P<0.05) and decrease MDA, MAO content (P<0.01 or P<0.05) in blood serum, liver, heart, kidney and brain tissue.⑥The number of hippocampal cells and the levels were reduced, structure disordered, part of the cell size reduced, nuclear shape changed in model group. The changes of VitE group and three dosages of 99Tc-MDP groups were closed to the normal group, the degeneration and necrosis of hippocampus cells were reduced, the number and morphologically of cells were normal, the structure were clear.Conclusions: 99Tc-MDP may reduce the effect of aging induced by D-galactose and free radicals damage to the body, enhance immunity and play a role in delaying aging and having good anti-aging action. 99Tc-MDP may be developed as a drug that could prevent and treat senile disease. |
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