动物模型,基底动脉栓塞 z-bo 2020-08-08 543

　　(1) Reproduction method A pure white red-eye male guinea pig weighing 400-450g is anesthetized by intraperitoneal injection of sodium pentobarbital at a dose of 35 mg/kg body weight, and then the animal is placed in a supine position, the head is fixed with a special head frame, and the trachea is inserted. Tube, spontaneous breathing, cut the left carotid artery, insert a heparinized arterial catheter at the proximal end, measure the mean arterial pressure (MABP) with a pressure sensor and a preamplifier, and use the A/ of the laser Doppler flowmeter The D converter converts the information and inputs it into the computer application software for recording and analysis. Open the right auditory bubble through the ventral approach to expose the cochlea, separate the sternohyoid muscle and the long head muscle attached to the occipital base in the middle, expose the occipital skull base, grind a bone window, expose and free the basilar artery, and use filter paper Wrap with strips; separate the right carotid artery, and pass a silk thread under it for ligation. The ligation thread is tied with a single knot but not tightened. Use a cotton swab to wipe off the mucoperiosteum of the cochlear base and lateral wall, fix the laser Doppler flowmeter probe with a three-dimensional fixator, make it flat on the cochlear base and lateral wall, and measure the blood flow of cochlea (CBF) ), after CBF and MABP are stable, record 5 minutes as the basic level before induction embolization, then tighten the ligature to ligate the right carotid artery, place 2 drops of 40% FeCl3 aqueous solution on the filter paper strip covering the basilar artery, and continuously record the CBF And MABP 50min. The data of CBF and MABP are both 100% before the induction of embolism, and the percentage changes of CBF and MABP after the induction of embolism are calculated. Finally, the data stored in the computer are processed for paired t-test.

　　(2) Model characteristics 5-10min after induction by this method, the CBF of the model animal began to decrease, compared with before induction, the difference was extremely significant; with the extension of the induction time, the decrease value of CBF gradually increased. The difference before induction is also extremely significant; in the entire modeling process, the mean value of CBF compared with before induction, the difference is also extremely significant, but MABP has no significant change. Since the vertebrobasilar artery and the carotid artery have a cerebral artery ring (willis circle) to communicate with each other, when making the animal model of basilar artery embolization and inner ear ischemia, the cerebral artery ring should also consider the formation of collateral blood supply problems after the basilar artery embolization. In this method, one carotid artery is cannulated, the other carotid artery is ligated, and then basilar artery embolism is induced, so that the blood flow of the basilar artery blood supply area decreases. The inner ear ischemia model established in previous research reports mostly used cochlear action potentials, brainstem auditory evoked potentials, and common histopathological changes as observation indicators to indirectly judge the changes in inner ear microcirculation. Some use biological microsphere technology to roughly estimate CBF changes, or simply use laser Doppler technology for CBF measurement, without considering the impact of blood pressure fluctuations on CBF. In this study, laser Doppler technology was used to directly measure the changes in CBF before and after basilar artery embolization. At the same time, the MABP was measured and input into the computer synchronously with the CBF signal. It was not only intuitive, but also accurately calculated the changes in CBF and MABP, and observed the effect of MABP on CBF.

　　(3) Comparative medicine This method can induce basilar artery embolism in guinea pigs, which provides an ideal experimental animal model for the study of the mechanism of clinical arterial embolism in the inner ear microcirculation disorder and the development and application of antithrombotic drugs. Due to the increasing number of disorders of inner ear microcirculation caused by arterial embolism, it is necessary to make an animal model of the embolism of the inner ear artery. But the method of establishing this animal model is still a problem that needs improvement. The model making method selects the basilar artery near the anterior inferior cerebellar artery before embolization. Whether the inner ear artery comes directly from the basilar artery or the anterior inferior cerebellar artery, the blood supply to the inner ear can be reduced. At present, there are many methods used to induce thrombus formation, such as photochemical method, electric current stimulation method, chemical reagent induction method and so on. However, the manufacturing method adopted in this model is low-cost, simple to operate, accurate in the embolization position, and the pathological changes of the embolized artery are similar to humans. The time required for the basilar artery embolism induced by this method is appropriate, so that the changes in CBF can be effectively recorded when antithrombotic drugs are studied in animal models. In summary, the use of this method to induce basilar artery embolism resulted in the reduction of inner ear CBF, which provided an ideal animal model for the study of inner ear microcirculation disorders and the study of antithrombotic drugs. The treatment of obstructive diseases has positive significance.