动物造模 z-bio 2023-11-21 1011

　　1. Animal model material: SD rats, female, 180-250g; Medication: Anesthetics.

　　2. Method of modeling: After anesthesia, rats were exposed to the right sciatic nerve. At the point closest to the bifurcation of the sciatic nerve, the nerve was dissociated from the attached tissue, and four 4-0 chromium catgut threads were applied. The nerve was loosely ligated until the outer membrane of the nerve was slightly compressed, with each node spaced 1.0mm apart; The sham surgery group underwent the same surgery without ligation.

　　3. Modeling principle: A model of sciatic nerve injury caused by chronic compression.

　　4. Compared with the sham surgery group, the mechanical pain threshold of the model group was significantly reduced 4 days after injury. After 7 and 14 days of surgery, the pain threshold remained stable at a lower level, known as a state of pain sensitivity.

　　5. After modeling, the pathological and biochemical changes showed that the synaptophysin positive products were brownish yellow granules or dots of relatively consistent size, or irregular island shaped with uneven thickness, mainly limited to the gray matter, with a small amount of immune positive fibers distributed in the white matter. The positive products of synaptophysin are distributed in the cytoplasm, but not in the nucleus. After re staining with hematoxylin, the nucleus appears light blue. The positive products of synaptophysin in the surgical spinal cord of the sham surgery group were significantly lower than those of the model group.

　　In the sham surgery group, there were a small number of glial fibrillary acidic protein positive cells expressed in layers I and II of the dorsal horn of the spinal cord, which were dark blue and distributed in the cytoplasm of astrocytes. The cell body was small, the protrusions were fine, and the staining was light, forming a double marker with synaptophysin immunopositive products. The main characteristics of glial fibrillary acidic protein positive cells on the injured side of the model group are: ① the cell body of glial fibrillary acidic protein positive cells in the affected side of the spinal cord becomes larger, the protrusions become thicker, forming a type of hypertrophic astrocytes; ② The number of glial fibrillary acidic protein positive cells in the I and II layers of the dorsal horn of the affected spinal cord significantly increased, indicating a consistent response of astrocytes to the site of chronic compressive injury. From a visual perspective, the positive products of glial fibrillary acidic protein in the spinal cord on the surgical side of the sham surgery group were significantly lower than those of the model group.

　　6. Precautions: Surgical instruments should be strictly disinfected to prevent surgical infections. Surgical trauma should be minimized and sterile operations should be strictly carried out.