动物造模,Ⅰ型变态反应模型 z-bio 2021-03-29 243

　　1. Active allergic conjunctivitis induced by ovalbumin

　　(1) Reproduction method: Add 1 ml ovalbumin phosphate buffered saline (PBS) (100μg ovalbumin, 10-20 mg aluminum potassium sulfate, pH 7.4 (including) intraperitoneal injection in rats or guinea pigs. 14 days later, 10-20μl of 1 mol/LDDT per eye drops can eliminate the conjunctival mucus barrier and improve the onset effect. 15 minutes later, inject 1 ml of 0.125% Evans blue solution intravenously at a dose of 1.25 mg/100 g body weight to judge Vascular permeability changed, and immediately challenged with 10μl of 5% ovalbumin PBS solution. 10μl of 5% ovalbumin PBS solution was used to challenge histological changes without injection of Evans blue. (2) Model features: give Rats are injected intraperitoneally with ovalbumin to produce IgE antibodies, IgE and F from conjunctival mast cells. Receptor binding and active sensitization. When antigens are used for local attack, activated mast cells degranulate and release allergic mediators, thereby increasing the local Vascular permeability accompanied by local eosinophil infiltration. Injection of Evans blue can penetrate the eye tissue and cause tissue edema. Vascular permeability can be changed according to the degree of chemical reaction, eosinophil infiltration, and mast cell degranulation Measured with the optical density of conjunctival tissue extracts to reflect the degree of conjunctival hypersensitivity. DL-Dithiothreitol (DDT) is a mucolytic agent that can destroy the conjunctival mucus barrier function, so high molecular weight ovalbumin can penetrate It penetrates the conjunctiva and binds to the IgE antibody in the tissue, thereby promoting abnormal eye reactions. (3) Comparative Medicine Ocular allergy is a type 1 allergy mainly mediated by mast cells. Bacterial conjunctivitis, vernal keratoconjunctivitis, atopic keratitis Conjunctivitis and giant papillary keratoconjunctivitis mainly involve type I allergies. There are many ways to induce type I allergies, but the most commonly used animals are rats, guinea pigs and mice. This model method is for type I allergic drugs The conventional screening method is objective, simple and fast (obvious symptoms of conjunctivitis appear 10 minutes after the onset, reach a peak at 30 minutes, and disappear after 1 hour), and the screening results are consistent. The clinical efficacy is basically the same. 2. Antigen-induced allergic conjunctivitis (1) Replication method Collect female guinea pigs or female mice, and apply 1.25 mg of ragweed powder (Ambrosiaartemisiaefolia) to the nasal cavity and subconjunctiva of the animal with a 10μl micropipette. On the curved ridge. /d, for 5 consecutive days, guinea pigs need to be boosted again in 8-12 days. On the 15th day, administer antigen to guinea pigs or mice, and spray 1.25 mg of ragweed powder onto the subconjunctival curve. Twenty minutes after antigen challenge , Determine the state of conjunctival hyperemia and edema under a slit lamp to determine the standard of active allergic conjunctivitis induced by the same ovalbumin.

　　(2) Model characteristics The use of Dax powder to repeatedly contact the nasal mucosa and conjunctiva of normal guinea pigs or mice will stimulate the production of specific IgE antibodies in the conjunctival tissue and the production of mast cell Fc on the conjunctiva, which makes the receptors actively allergic. . When antigen attacks, the combination of antigen and antibody will cause local mast cells to degranulate and release allergens, thereby increasing the permeability of local blood vessels, causing congestive congestion and edema, accompanied by eosinophil infiltration. The degree of conjunctival hypersensitivity is determined by the degree of conjunctival hyperemia, eosinophil infiltration and mast cell degranulation. (3) Comparative medicine. The etiology and clinical manifestations of human eye allergic conjunctivitis and hay fever conjunctivitis caused by this method are very similar: ①The antigen used is the most common aerial antigen. (2) The application method is the most natural allergen contact method. ③ No adjuvant is needed. ④ Animals can cause high levels of anti-ragweed IgE and obvious clinical and histological symptoms of allergic conjunctivitis. The method is reproducible, economical, practical, fast and easy to operate, and can be used as a screening method for Bacillus subtilis conjunctivitis and other anti-allergic agents. The number of days of administration before immunization of animals is the same as that of ragweed powder. The number of drops per day is determined by the pharmacodynamic and pharmacokinetic properties of the tested drug. 3. Passive allergic conjunctivitis caused by ovalbumin

　　(1) Copy method 10μl of serum from guinea pigs or rats sensitized to ovalbumin was injected into the subconjunctiva of normal guinea pigs or rats to sensitize the passive conjunctiva. Challenged. Animals with altered vascular permeability were injected intravenously with 1 ml of 0.1% Evans Blue solution containing 100 μg ovalbumin. Only 10 μl of 1% ovalbumin PBS solution was injected intravenously into animals with definite clinical and histological changes. Evans blue solution. (2) Model characteristics: Subconjunctival injection of the serum of sensitized guinea pigs or rats (rich in IgE antibodies) into normal guinea pigs or rats. IgE binds to Fc receptors on conjunctival mast cells and passively sensitizes them. When antigens attack, mast cells release allergens, increasing local vascular permeability and conjunctival eosinophil infiltration. By measuring the amount of Evans blue penetrating the eyelids and conjunctiva and the number of eosinophils, the degree of conjunctival hypersensitivity can be reflected. .. (3) Comparative medicine The model method can be used as a routine screening method for anti-type I allergic drugs. The route of administration and duration of administration are determined by the pharmacokinetic and pharmacokinetic properties of the tested drug.

　　4.48/80 allergic conjunctivitis () (1) Copy method Collect a healthy adult rat and inject 1 ml of 0.125% Evans blue solution intravenously at a dose of 1.25 mg/100 g body weight. After 15 minutes, use 48/801 mg deeper than 10μl. Inject PBS (pH 7.4) into the eye. Twenty minutes later, the animal was sacrificed and the eyelids and eyeballs were removed. For animals with definite clinical and histological changes, only 10 μl of 48/80 PBS solution can be used to attack the animals without injection of Evans Blue. (2) Model features 48/80 directly induce non-immune degranulation of mast cells by measuring the amount of Evans blue that penetrates the eyelids and conjunctiva, release allergic mediators and conjunctival blood vessels, increase permeability and conjunctival eosinophil infiltration . The degree of conjunctival allergic reaction. (3) Comparative Medicine 48/80 is a mast cell degranulation agent widely used in in vitro and in vitro studies. It is commonly used to study the efficacy of drugs that inhibit the degranulation of various immune and non-immune mast cells. Use the experimental drug 2 days before the 48/80 eye drops. The number of drops per day is determined by the pharmacodynamic and pharmacokinetic properties of the tested drug.

　　5. Allergic conjunctivitis caused by histamine

　　(1) Copy method Inject 1 ml of Evans blue solution (1 g/L) into the guinea pig vein, and then inject 20 μl of the test drug into one eye of the model. Animals: 30 minutes after 40 minutes of topical administration, guinea pigs are anesthetized and challenged with histamine 300n9/μl subconjunctival injection or histamine solution 25/μl (7.5-10μg/ml) eye drops to quantify the response. (2) Model characteristics Histamine is an allergic mediator and the main component that causes allergic conjunctivitis. Subconjunctival injection of histamine in guinea pigs can directly increase the permeability of conjunctival blood vessels and cause tissue edema.

　　(3) Compare the allergic conjunctivitis model produced by this method in medicine. The method is simple and easy to implement and easy to control the condition, so it is suitable for the research of anti-allergic ophthalmic drug screening.