动物造模,药效评价,干眼模型 z-bio 2024-08-07 313

　　1. Dysfunction of meibomian gland and strong evaporation type rabbit dry eye model. Some special types of mice already have developmental disorders of meibomian gland. Shortly after birth, Rhino mice may experience thickening and excessive keratinization of the meibomian gland duct epithelium due to epithelial variations and developmental abnormalities, leading to meibomian gland dysfunction. Injecting human monoclonal anti DNA antibodies into mice can cause chronic blepharitis, excessive proliferation of meibomian glands, infiltration of inflammatory cells in meibomian glands, and dysfunction of meibomian glands.

　　2. Environmental factors lead to excessive evaporation in a mouse dry eye model. Barabino et al. placed 8-12 week old BALB/c female mice in a dry environment (artificial climate chamber) with constant relative humidity, temperature, and air flow. The dry environment was set at a relative humidity of 18.5% ± 5.1%, temperature of 21-23 ℃, and air flow of 15L/min; The control group of mice of the same age were placed in a normal environment with a relative humidity of 50% to 80%, a temperature of 21-23 ℃, and no air flow. The author observed that mice placed in a dry environment had significantly reduced tear secretion on days 3, 7, 14, and 28, with corneal fluorescein staining mainly in the central and nasal regions; The conjunctival tissue section shows an increase in the number of epithelial cell layers, thickening of the outer layer, and a significant decrease in the density of goblet cells. In some experiments, researchers aimed to accelerate the evaporation of animal tears by continuously exposing the animals to air blowing devices such as fans and continuous airflow. In this method, the authors optimized and refined the dry environment setting and inspection methods to avoid the impact of animal tension on tear film stability.

　　Nakamura et al. used a surgical blade to scrape the central area of the corneal epithelium in male mice, and then placed them in a dry room with constant relative humidity, temperature, and air flow. They found that the tear secretion at 2, 6, and 12 hours was significantly reduced compared to the normal control group. At 6 hours, there was slight corneal staining around the original scratch area, and at 12 hours, it progressed and expanded into plaque like lesions. Histopathological examination revealed corneal epithelial cell shedding and thinning around the original wound, and immunohistochemistry showed significant apoptosis of corneal epithelium at 6 hours.

　　3. Exposure factors lead to the exposure of eyelid sutures in a mouse dry eye model with excessive evaporation. Taking this as an example, the specific operation method is introduced: Wistar rats are anesthetized by intraperitoneal injection of an equal amount of ketamine and diazepam mixture. The upper and lower eyelids are sutured with No. 1 black silk thread and fixed to the corresponding skin around the eyes to fully expose the cornea. The rats are marked and timed.

　　Tian Mingxia et al. developed a rat model of exposure induced dry eye syndrome, and the results of fluorescein staining showed that the ocular surface damage of this model worsened with prolonged exposure time. The Schirmet test also showed that with prolonged exposure time, there was a compensatory increase in tear secretion, but after 24 hours of exposure, there was a decrease, which may be related to excessive tear evaporation and insufficient tear gland function. This model is easy to establish and can cause changes in the ocular surface of dry eye syndrome in a short period of time, providing convenience for further research on the pathogenesis and treatment methods of dry eye syndrome.

　　4. Nakamura developed a creative model to induce abnormal tear dynamics in mice with tear dynamics. Female mice were placed on suspended plastic tubes and subjected to a fixed airflow for over 15 hours per day, while the rest of the time was kept in a dry cage for 10 consecutive days. The results showed a significant decrease in blink frequency, a significant increase in residual fluorescein, and a decrease in tear secretion. The corneal fluorescein staining score was significantly different from the control group, and the morphology was similar to that of superficial punctate corneal disease in humans. Histopathology shows thinning of corneal epithelium and abnormal size and arrangement of stromal cells. On the 10th day, the corneal epithelium and stromal layer under the microscope became thinner and the permeability increased significantly. Under electron microscopy, bright cells with microvilli and folds are rarely seen. The principle of this model is that the fixation function of both eyes plays an important role in maintaining body balance. In order to maintain balance in the plastic tube, female mice force both eyes to continuously fixate forward, reducing blinking and prolonging eye surface exposure time, ultimately leading to a decrease in tear excretion rate. This is similar to shallow punctate corneal lesions caused by prolonged eye use such as facing screens, driving, and reading. The above observations indicate that the pathogenesis of this disease not only includes changes in corneal epithelial integrity, but also involves abnormal differentiation.

　　5. A mixed model of dry eye in mice caused by drug combined with environmental factors leading to tear deficiency and excessive evaporation was established by injecting Botulinum toxin (BTX) into the lacrimal gland through the conjunctiva and combining it with environmental factors. The specific method was introduced as follows: 6-8 week old female (CBA/J mice) were anesthetized satisfactorily, and 20 milliunits (0.05ml) of BTX-B were injected into the lacrimal gland through the conjunctiva using a fine needle (No. 33 needle) under a surgical microscope; Place the rat cage in front of the blower device, control the blower flow rate (400ft/min) for 5 hours a day and 5 days a week, and maintain a constant ambient temperature and humidity (70-750F, 20% -35%).

　　The secretion of lacrimal glands is regulated by the autonomic nervous system, with the parasympathetic nervous system playing a major role. Botulinum toxin inhibits the release of acetylcholine mediated by calcium ions from parasympathetic nerve endings, leading to denervation of acini and reduced tear secretion, resulting in dry eye symptoms. Some studies have shown that BTX-B has a faster and more diffuse effect than BTX-A. Suwan arachon et al. used the above method to inject botulinum toxin B into the lacrimal gland of CBA/J mice for 3 days, and immediately showed a decrease in tear secretion and corneal fluorescence staining. The decrease in tear secretion lasted for at least 2-4 weeks, and a brief rebound phenomenon may occur at 8 weeks. The tear secretion increased slightly, but returned to normal at 10 weeks, while corneal fluorescence staining continued to exist; Additional environmental factors exacerbate the damage to corneal epithelium; Pathological histology examination showed no infiltration of inflammatory cells in the lacrimal gland and conjunctival tissue. This method is simple, easy to implement, convenient, and fast, without frequent repeated administration. Local administration has minimal systemic adverse reactions, and the dry eye model produced has a long duration, stability, and reliability, simulating the chronic course of non Sj ö gren's syndrome in humans.