How to prepare an animal model of lauric acid-induced vasculitis obliterans in rats?

  (1) Reproduction method Male Wistar rats weighing 280-320 g were anesthetized by intraperitoneal injection of 3% pentobarbital sodium at a dose of 35 mg/kg body weight. The right femoral artery was fixed and separated by the animal supine, and the blood was blocked by the artery clamp in the middle of the femoral artery. Then lauric acid was injected, the total volume injected was 0.2ml. First, inject lauric acid into the proximal direction 1.0cm below the arterial clip, and then inject the remaining lauric acid into the distal direction of the femoral artery. The standard of injection is that when the blood vessel is obviously filled and slightly white without obvious swelling, the removal of the syringe should be gentle at the end of the injection. 15 minutes after the injection of lauric acid, the arterial clamp was opened, the blood flow was restored, and bleeding and hemostasis were observed. After the animal has completely stopped bleeding and the limbs on the surgical side have obvious changes, all layers of tissue can be sutured layer by layer. Approximately 5 minutes after injection of lauric acid into the femoral artery of the rat, the skin temperature of the affected foot decreased, the skin became pale and then blue, the arterial pulsation weakened or disappeared, and the affected plantars turned black the next day, and gradually developed upwards, forming gangrene And mummification. A few animals showed edema, erosion and inflammation of the affected limb after operation. All rats had pain, claudication and dragging in the affected limbs after the operation. Within 2 weeks, the rats had part of the gangrene of the affected limbs fell off, and the shedding rate was 90%. Pathological examination revealed that there were different degrees of thrombosis in the arteries of the affected limbs, the arterial endothelium had different degrees of hyperplasia, and the media and adventitia also showed obvious inflammatory cell infiltration. The evaluation of this model is divided into overall evaluation and pathological evaluation: the overall evaluation mainly grades the degree of swelling of the affected limb, the degree and scope of gangrene and mummification lesions (grade 0: normal; grade 1: lesions confined to the nail; grade 2 : The lesion is confined to the toes; Grade 3: The lesion is confined to the feet; Grade 4: The lesion is confined to below the knee joint; Grade 5: The lesion is confined to the knee joint above); In terms of pathological evaluation, the entire rat model is disabled The right lower limb was removed and fixed with 10% formaldehyde, and then decalcified with 10% nitric acid after 3 days. The toes, upper and lower ankle joints, and thighs were cross-sectioned and HE stained. For each specimen, 4 four-site sections were taken and placed on a pathological section, and then the arterial thrombosis was graded under a microscope ( Grade 0: No thrombosis; Grade 1: 1 thrombus; Grade 2: 2 to 3 thrombus; Grade 4: 4 or more thrombus), at the same time, respectively, the arterial wall inflammatory cell infiltration, fibrosis and thrombus muscularization and recanalization Wait for observation.

  (2) Model features: This model is made by direct injection of lauric acid into the artery, so the model has a high success rate, simple method, good repeatability and stability, and reagents are cheap and easy to obtain, especially through this multi-site , Semi-quantitative statistical inspection improves the scientificity of the experimental data, and the results are reliable.

  (3) Comparing medicine. Compared with the method of using ZT medical glue, this model has a low infection rate in the operation area and a low delayed healing rate of the incision. It avoids the irritation reaction of the allogeneic antigen of the ZT glue and its caused The compression of the femoral artery directly caused by the inflammatory reaction of various foreign antigens. The animals replicated by this model conform to the vascular occlusion mechanism of the human body under the pathological state of TAO, and their symptoms, signs and histopathological changes are basically consistent with the changes in clinical TAO patients.