Regulative Function Of Doxycycline On The Expression Level Of Mmp-3 In Degenerated Lumbar Intervertebral Disc

Objective To study the regulative function of Doxycycline on the expression level of MMP-3 in degenerated lumbar intervertebral disc, to seek for a new pharmacological treatment for the patients who have degenerated lumbar intervertebral disc.Method 1. To divide 40 rats into an experimental group and a contrastive group stochastically by random number table, each group 20 rats. Then complete the animal model. From the 8th week after operation, the animals of the experimental group were injected with Doxycycline 25mg, two times in the daytime and in the night per day. Those of the control group with the equal volume of saline per day.Two weeks late,the tissue of degenerated lumbar intervertebral disc was taken, A part was put into 10% neutral formalin to be fixed, another part was deposited in the liquid nitrogen. 2. Immumo-histochemistry Test. To Take the sample which was fixed by formalin, then to test the expression of MMP-3 in degenerated lumbar intervertebral disc by the way of SP of immumo-histochemistry. The positive part expression are yellowish brown, which mainly exists in the cytoplasma.To test average light density value of the experimental group and the contrastive group by Image-Pro Plus6.33. Western—bloting Test. The sample, which was in liquid nitrogen, was extracted the vertebral pulp protein in lumbar intervertebral disc, then use X development to measure the average relative content of protein. And to image by JS-780 completely automatic gelatin analysis system then to test the average comparative contentResults In the Immumo-histochemistry Test, The expression of MMP-3 in the experimental group was weak positive while the control group was positive. And the result of the average light density value of the experimental group and the contrastive group, the MMP-3 expression of the experimental group was lower than the control group.(P< 0.01).In the Western—bloting Test, to test the ratio vale of the MMP-3 image and the Actin, and take the ratio as MMP-3 comparative content, the result showed the value the experimental group was lower than the control group.(P< 0.01).Result 1. The animal model of SD rats degenerated lumbar intervertebral disc was successful; 2. The Doxycycline hypodermic injection can cause the local skin ulcer at injection spot; 3. The new MMPs inhibitor—Doxycycline can decrease expression level of MMP-3 lumbar intervertebral disc.