动物造模,角膜内皮损伤动物模型 z-bio 2021-12-04 389

　　(1) Breeding method For experimental rabbits weighing 2 to 2.5 kg, drip 0.25% chloramphenicol eye drops into the eyes twice a day for 3 consecutive days before freezing, and instill 2 ml/kg on the 4th day. The weight passes through the ear veins. Use 1.5% sodium pentobarbital anesthesia and 0.4% benoxil solution to perfuse the ocular surface anesthesia. Immerse a copper cryogenic probe with a diameter of 8 mm in liquid nitrogen for a few seconds, and then take it out. When the probe temperature reaches -120°C, place it perpendicular to the center surface of the rabbit's cornea and allow it to fully contact for 5-15 seconds.

　　(2) Model features: The corneal endothelial cells in the frozen area of the model animal are completely destroyed, and the boundary between the injured area and the uninjured area is clearly visible. Freezing for 5 seconds and 15 seconds will cause corneal endothelial defects in similar areas, but freezing for 5 seconds will reduce corneal edema. Three days after the injury, a small part of the corneal endothelium healed, and four days after the injury, all corneal endothelial defects were covered by regenerated endothelial cells of different sizes and irregular shapes. Twelve days after injury, the regenerated endothelial cells tend to be uniform in size and polygonal in shape.

　　(3) The stability and reliability of this model in comparative medicine are very important, because the establishment of a corneal endothelial injury model is the basis for further research on spontaneous reactions and drug effects after endothelial injury. The methods of replicating corneal endothelial models mainly include mechanical injury, ultrasound injury, alkali burn and total hypothermic corneal injury. The mechanical injury method usually uses trefin to excavate the animal’s own cornea, wipe the endothelial cells with a cotton swab, and then re-implant the corneal graft into the autologous implant bed. This method is difficult to operate. Special equipment will be placed. The damage of the endothelial layer has relatively little effect on the basement membrane of the cornea and other tissues, but it increases the possibility of intraocular infection. Ultrasound injury is to cut the lens emulsifier into the anterior chamber through the corneal annulus incision, so that the endothelium is damaged by non-contact ultrasound. This method is similar to the method of mechanical damage. The alkaline burn method is a method of endothelial injury, in which a round filter paper of a certain diameter soaked in a 1 mol/LaOH solution is placed on the surface of the rabbit’s cornea for 1 minute. This method is very simple, but the endothelium is a biphasic healing process: 1 week after the burn, the endothelial defect is completely covered by endothelial cells that migrate in a straight line, but the endothelial cells regenerated in this layer undergo secondary within 1 week Sexual decay and easily complicate experimental results. The method of freezing the entire cornea is to place a cold metal cryoprobe on the surface of the animal's cornea for a period of time, thereby damaging the endothelium. This method is simple and easy to implement. This model technology uses a frozen copper probe with a diameter of 8 mm and a temperature monitoring device to unify the freezing temperature, and select an appropriate freezing time to dynamically observe the healing process of endothelial injuries. This simplifies your research. Use drugs that promote the healing of the corneal endothelium. An animal model of endothelial injury with good reproducibility.