动物造模,药效评价,慢性压迫性坐骨神经损伤 z-bio 2024-08-07 429

　　1. Modeling material animal: SD rats, female, 180-250g; Drug: Anesthetic.

　　2. Modeling method: After anesthesia of rats, the right sciatic nerve is exposed. At the closest bifurcation of the sciatic nerve, the nerve is freed from the attached tissue, and four 4-0 chromium sheep intestines are placed on it. The nerve is loosely ligated until the outer membrane of the nerve is slightly compressed, with a distance of 1.0mm between each knot; The sham surgery group underwent the same surgery but without ligation.

　　3. Modeling principle: Chronic compression causes sciatic nerve injury model.

　　Compared with the sham surgery group, the model group showed a significant decrease in mechanical pain threshold 4 days after injury. The pain threshold remained stable at a low level for 7 and 14 days after surgery, indicating a state of pain sensitivity.

　　5. Pathological and biochemical changes after modeling show that the positive products of synaptophysin are uniformly sized brownish yellow granules or dots, or irregularly shaped islands with uneven thickness, mainly limited to gray matter, with a small amount of immunopositive fibers distributed in white matter. The positive products of synaptophysin are distributed in the cytoplasm, but not in the nucleus. After hematoxylin counterstaining, the nucleus appears light blue. The number of immunopositive products of spinal cord synaptophysin on the surgical side in the sham surgery group was significantly lower than that in the model group.

　　In the sham surgery group, there were a small number of deep blue glial fibrillary acidic protein positive cells expressed in layers I and II of the spinal dorsal horn, which were distributed in the cytoplasm of astrocytes. The cell bodies were small, the protrusions were thin, and the staining was light. They formed a double label with the immunopositive products of synaptophysin. The main characteristics of glial fibrillary acidic protein positive cells on the injured side of the model group are: ① The cell bodies of glial fibrillary acidic protein positive cells on the affected side of the spinal cord become larger and their protrusions become thicker, forming a type of fat large astrocytes; ② The number of glial fibrillary acidic protein positive cells in the first and second layers of the spinal dorsal horn on the affected side significantly increased, indicating a consistent response of astrocytes to the site of chronic compressive injury. Intuitively, the number of glial fibrillary acidic protein immunopositive products in the spinal cord on the surgical side of the sham surgery group was significantly lower than that of the model group.

　　6. Precautions: Surgical instruments should be strictly disinfected to prevent surgical infections, surgical trauma should be minimized, and aseptic operation should be strictly enforced.