动脉粥样硬化斑块,动物模型 z-bo 2020-08-06 538

　　(1) Reproduction method male experimental rabbits weighing about 1.5kg were anesthetized by intravenous injection of 25% urethane at a dose of 1g/kg body weight, and exposed and freed the right common carotid artery (CCA) and right internal carotid artery ( ICA) and right external carotid artery (ECA). Temporarily clamp the aneurysm with a straight clip on the proximal side of the right CCA about 2 cm from the ICA, ECA bifurcation and the beginning of the right ICA, and ligate the exposed right ECA about 1 cm distal to the carotid artery (CA) bifurcation . Heparin sodium 200U/kg was injected from the ear vein for 5 minutes, and a fine needle was used as a puncture needle to puncture the artery into the guide wire from the proximal side of the right ECA ligation, and bundle the cowhide tendon at the proximal side of the puncture point to prevent bleeding. Withdraw the right CCA arterial clip, continue to enter the guide wire, remove the puncture needle (to prevent bleeding at the puncture site, tighten the cowhide tendons), guide the 2.0mm balloon catheter through the right ECA to the right CCA into the aortic arch, Then the airbag is inflated to a pressure of 810.6kPa (8atm). The aortic arch retreats to the right ECA, mechanically expands the right CCA, repeats 3 times, 30s each time, peels off the intima of the right CCA and mechanically damages it, removes the catheter, ligates the right ECA near the puncture point, and feeds with standard mixed feed at room temperature. The rabbits were anesthetized by intraperitoneal injection of 10% chloral hydrate before being sacrificed and fixed on the operating table. A midline neck incision was made to expose bilateral CCA. The 2cm segment of CCA from the proximal side of the carotid artery bifurcation was taken for examination. The left CCA was used as a control, and the observation was performed under light microscope and electron microscope. Those who sent the light microscope were fixed with formaldehyde and embedded in conventional paraffin, and the section thickness was about 5μm, and the HE staining was routinely observed; those who were sent the electron microscope were fixed with glutaraldehyde. A microscope and a computer analysis system were used to calculate the inner diameter of the cross-sectional lumen, the thickness of the intima and the media, and the ratio of the intima/media thickness. On the 15th day after the operation, the neointima layer was thickened, and the degree of stenosis was more obvious than that on the 3rd and 7th day. Under light microscope, adherent thrombosis was seen on the 3rd day after the operation. On the 7th day after the operation, fresh thrombus was rare. The more obvious smooth muscle cells shifted and grew, and the intima was thickened; on the 15th day after the operation, the intima was significantly thickened, and the main components were vascular smooth muscle cells and a matrix rich in collagen. Under the electron microscope, on the 15th day of balloon expansion, the endothelial cell nucleus was oblong, with medium electron density, scattered mitochondrial cells were seen in the cytoplasm, and new VSMCs could be seen next to the endothelial cells. The nucleus was irregular and part of the nuclear membrane was invaded. A large number of organelles can be seen in the cytoplasm, mitochondria, rough endoplasmic reticulum, and plasma membrane vesicles are extremely abundant, indicating that their functions are extremely active, and a large number of collagen fibers can be seen around such cells.

　　(2) Model characteristics The mechanical damage of the inner membrane of this model directly causes the damage and exfoliation of the inner membrane, and the fracture of the inner elastic plate, which greatly accelerates the deposition of lipids and calcium salts and the invasion of inflammatory cells in the bloodstream; rabbits are used as Model animals avoid the high cost and inconvenient feeding of large animals (pigs, dogs). The carotid arteries of rats are thin, a microscope must be used, and the operating field is small and inconvenient to operate. Rabbits are easy to raise, and the carotid arteries are thicker and easy to separate. Carotid arteries and catheters are operated under naked eyes and have a high success rate. This model has obvious stenosis at half a month after surgery, and is suitable for the establishment of carotid PTA animal models.

　　(3) Comparative medicine. The arterial clip for the production of this animal model is ligated at the start of ICA and 2cm proximal to the bifurcation of the CCA to free the carotid artery balloon to expand the endarterial exfoliation segment, which basically simulates the clinical carotid artery PTA. The pathological morphology of intimal hyperplasia after angioplasty in this model is similar to the pathological process of restenosis after human balloon angioplasty, including smooth muscle cell proliferation, subintimal migration and extracellular matrix hyperplasia; and intimal tearing after angioplasty Cracks, platelet accumulation, and dissection formation are similar to pathological changes after clinical coronary angioplasty. But there are also shortcomings, such as the lack of calcification in the lesion and the typical characteristics of human atherosclerosis such as the central lipid pool.