疾病动物模型,肿瘤模型 z-bio 2022-11-08 455

　　There are many ways to replicate animal tumors, such as irradiating laboratory animals with radiation or intravenously or locally injecting radioisotopes; using various chemical carcinogens (alkylating agents, polycyclic aromatic hydrocarbons, aromatic amines, amino azo dyes, nitrous Amines); use of phytotoxins (such as cycads, safrole, etc.); use of metals (such as chromium, nickel, arsenic, cadmium, etc.); use of RNA and DNA tumor viruses; use of a variety of carcinogenic mycotoxins (of which the most carcinogenic effect Those are aflatoxins), etc., which can induce various tumors.

　　The number of induced tumor models is the first among induced animal models. Generally, carcinogens are used to cause tumors in animals through oral, injection, burying and smearing.

　　There are also many reports of viruses that can induce tumors in animals. For example, mouse leukemia virus (MLV), chicken leukemia virus (ALV) and feline leukemia virus (FLV) can cause leukemia in rats, mice, chickens and cats, respectively. Rous chicken tumor virus can cause sarcoma in a variety of animals such as voles, chickens, ducks, quails, monkeys, and snakes. Feline Sarcoma Sarcoma (FSV) can cause sarcoma in rats, cats, dogs and monkeys. Human adenovirus can induce sarcoma and lymphoma in mice and field mice.

　　(1) Induced tumor animal model

　　1. Liver cancer 　Diethylnitrosamine (DEN) induces liver cancer in rats: Take a closed group of rats weighing about 250g, male and female. Raised in cages by sex. In addition to ordinary food, carcinogens are fed, that is, 0.25% DEN aqueous solution is used to gavage the stomach at a dose of 10 mg/kg, once a week, and the 0.025% DEN aqueous solution is put into a water bottle for the remaining 5 days and allowed to drink freely. A total of about 4 months can induce liver cancer. Or single use 0.005% mixed with drinking water orally for 8 months to induce liver cancer. 4-2 Methylamino benzene (DBA) induces liver cancer in rats: feed rats with 0.06% DBA feed, and the vitamin B2 in the feed should not exceed 1.5-2 mg/kg. A large number of liver cancers will be induced in 4-6 months. success. 2-Acetylamino acid (2AAF) induces liver cancer in mice, dogs, cats, chickens, and rabbits: Give adult rats a standard feed containing 0.03% 2AAF. An average of 2 to 3 mg of 2AAF per day (2AAF can also be mixed in oil to feed), after 3 to 4 months, 80 to 90% of animals will develop liver tumors. Diethylnitrosamine induces liver cancer in rats: The dose is 0.3-14mg/kg body weight per day, mixed with feed or drinking water, and 255/300 rats develop liver cancer after 6-9 months. Imino azotoluene (OAAT) induces liver cancer in mice: Apply 1% OAAF benzene solution (about 0.1ml containing 1mg) on the skin between the shoulders of the animal, once every other day, 2 to 3 drops each time, generally 100 Times. The first liver tumor appeared 7 to 8 weeks after the experiment, and about 55% of liver tumors in mice can be induced in more than 7 months. Or use 2.5mg OAAT dissolved in sunflower seed oil, subcutaneously injected 4 times into C3H mice, 10 days apart every day, it can also induce liver cancer. Aflatoxin induces liver cancer in rats: The daily feed contains 0.001 to 0.015 ppm. After being mixed into the feed for 6 months, the liver cancer induction rate reaches 80%.

　　2. Gastric cancer 　Methylcholanthrene induces gastric cancer in mice: Take about 20g of mice and pass them through the mucosa of the glandular stomach under aseptic operation.

　　Hang the knot containing methylcholanthrene (MC). The thread knot containing MC is made of ordinary thin thread. After the knot is tied at one end, the thread knot is placed in a small glass test tube containing MC, and the alcohol lamp is slightly heated to make the MC liquefy and penetrate into the knot. The MC concentration is 0.05～0.1g 20-methylcholanthrene into 10～20 threads. 4 to 8 months after surgical embedding can induce successful gastric cancer. With asymmetric nitrosamines at a dose of 0.25ml/kg body weight, all animals developed anterior gastric papillary carcinoma after 3 months, and 85-100% of them developed anterior gastric cancer after 7-8 months. Kunming species is the most sensitive. The A line is the second, and the 615 line has the worst sensitivity. In addition, methyl nitrosoacetate urea can be used to add 2 mg/kg body weight to the drinking water of BD rats, and drink it 5 times a week. After 520 days, all rats developed glandular gastric cancer.

　　3. Esophageal cancer methylbenzylnitrosamine (MBNA) induces esophageal cancer in rats: take Wistar rats weighing more than 100g, let them eat drinking water containing methylbenzylnitrosamine, and mix MBNA into the feed to make each The daily intake is 0.75～1.5mg/kg body weight. 80 to 100 days can induce esophageal cancer. Dihydrosafrole (Dihydrosafrole) can also be used, which is a condiment for the preparation of beer. Adding 25 to 10 thousand parts per million (2500 to 10000 ppm) of safrole in rat feed can cause 20 to 75% Esophageal cancer. Use 0.2% or 0.005% methylbenzylnitrosamine aqueous solution to feed the animals orally, once a day, the rat perfusion dose is 1mg/kg body weight, a case of esophageal papilloma was found on the 27th day, 154 days The first case of esophageal cancer was found, and the incidence of esophageal cancer at 11 months was 53%.

　　4. Lung cancer Diethylnitrosamine (DEN) induces lung cancer in mice: mice will be injected subcutaneously with 1% DEN aqueous solution once a week, each dose is 56mg/kg, the total dose of DEN reaches 868mg, and the observation time is about 100 days. The rate can reach 40%. When the total dose of DEN reaches 1176mg, the observation time is about half a year; the cancer rate can reach 94%. Urethane-induced lung adenocarcinoma: Mice (A strain, 1~11/2 months old) are more sensitive than rats, and each intraperitoneal injection of 0.1~0.3ml of 10% urethane saline solution is performed every 3~5 days. Note: A total of 2 to 3 months of injection, the dosage per mouse is about 100 mg, and the incidence of lung adenocarcinoma is 100% 3 months after injection, and most of them are multiple. This kind of induced tumor is benign. In addition, intratracheal injection of benzopyrene, ammonium sulfate aerosol, methylcholanthracene, etc. can be used to induce lung cancer. For example, 3,4 benzopyrene is injected into the trachea of monkeys (the mixture of 3-15 mg of benzoic acid and the same amount of Fe2O3) once a week for a total of 10 times. 2 out of 6 monkeys induce lung squamous epithelial cancer . Someone inhaled 100 rats with amine sulfate aerosol. After 13 months, all rats developed lung adenocarcinoma. Use 0.2% gelatin as a suspending agent to mix methylcholanthrene and inject it into the trachea of golden hamsters, each time 0.1ml (containing methylcholanthrene 5mg) once a week, a total of 6 times. After 53 weeks, 62.5% of the animals developed Lung cancer.

　　5. Nasopharyngeal carcinoma dimethylcholanthrene (MC) induces nasopharyngeal carcinoma in rats: Take a hard plastic rice tube with a diameter of 2 to 3 mm, and pull it into a cone with a small flame on an alcohol lamp. Each section is about 3.5 cm long, and the tube is filled Take crystal MC. One end of the small tube is sealed with fire to prevent the medicine from spilling, and the tip is punctured with a needle to make the MC overflow from the concubine. Take a white mouse weighing about 120g, both male and female. After ether anesthesia, insert the above-mentioned plastic tube containing MC into the nasal cavity from the front nostril. Use the small but thick end of the front nostril as the feature. Apply a little force to force the small tube into all In the nasal cavity, the tip can reach the nasopharyngeal cavity. Without additional fixation, the small tube can be left in the nasal cavity for a long time. When the predetermined time (more than half a year) or the animal dies on its own, the nasopharynx is fixed in 10% formalin, decalcified, embedded in paraffin, and serial sectioned. The cancer rate can reach more than 60%. Nasopharyngeal carcinoma induced by diethylnitrosamine nasal drip method: Take about 120g of white rats, both male and female, after ether anesthesia, use a flat-pointed 8-gauge needle, gently insert it from the front nostril, the needle tip can reach the nasopharyngeal cavity. 0.02ml (containing DEN6.7mg) of 1% Tween-80 newly prepared 33.3% DEN suspension by syringe infusion once a week, 15-20 times in total, can induce nasopharyngeal carcinoma.

　　6. Cervical cancer 　 Take female mice, use cotton yarn with 0.1 mgMC to tie the thread into the cervix with the help of a vaginal dilator and a sharpened curved needle under the state of the animal without anesthesia. Pass through the back of the right uterine horn to fix the knot on the cervix. The other end of the thread was fixed to the back muscles and the skin was sutured. After the thread was hung, penicillin was continuously injected for 2 to 3 days on the same day. To prevent postoperative infection. At a certain time (about half a year), the animals were sacrificed, and the cervical tissues were fixed with 10% formalin, embedded in paraffin, and sectioned continuously.

　　7. Colon cancer: Four-week-old male rats were injected subcutaneously with Dimethlhydrazine (DMH) once a week for 21 consecutive weeks, with 21 mg/kg of DMH each time. Animals were sacrificed 1 to 4 weeks after the last dose. The descending colon was fixed with Bouin solution, dehydrated, embedded in paraffin, and sectioned. The DMH used is first prepared into a mother liquor containing 400mg per 100ml, and 37mg EDTA is added, and the pH is adjusted to 6.5 with sodium hydroxide (0.1N) solution for later use.

　　(2) Animal model of transplanted tumor

　　Most of the anti-tumor drugs currently in clinical use are discovered through screening in animal transplantation tumor tests. The advantages of using animal transplantation tumors to screen drugs are: a group of animals are simultaneously inoculated with the same amount of tumor cells, the growth rate is relatively consistent, the individual difference is small, the survival rate of the inoculation is nearly 100%, the impact on the host is similar, and the therapeutic effect is easy to objectively judge , Can be transplanted continuously in the same species or the same strain of animals, long-term reserved for testing, the test period is generally short, the test conditions are easy to control, etc. Therefore, most of the current anti-tumor drug screening uses animal xenografts as the screening model. There are currently about 400 animal transplanted tumors preserved in the world, but there are only 20-30 types of tumors commonly used in screening tests. According to statistics in 1984, my country has established 64 common tumor strains of various animals and humans in the same line and the same species of animals. For example, mouse lung adenoma (HP615), mouse cervix tumor No. 27 (U27), mouse brain tumor 22 (B22), mouse lymphocyticemia (L615), nude mouse human liver tumor transplantation tumor and human Brain malignant glioma (NCS-1) and so on.

　　Animal tumors can be transplanted and passaged to cultivate the required tumor cell lines. Tumor strain is a tumor cell model whose histological type and growth characteristics have stabilized, and can be serially passaged in the same line or the same animal. Tumor transplantation in healthy animals is equivalent to living tissue culture, which can preserve tumor species for a long time for experimental use.

　　Two methods of transplantation of ascites tumor and solid tumor are commonly used in experiments. For tumors that produce ascites, a certain number of cells can be injected into the abdominal cavity of recipient animals to form ascites tumors or produce ascites. Solid tumor transplantation is also under aseptic conditions, the solid tumor is cut into small pieces of 2 to 3 mm and implanted under the skin of the recipient animal.

　　Autologous homologous animal tumor implants do not produce excretion phenomenon. The transplantation of the same animal can be combined with the injection of adrenal cortex hormones, anti-tumor drugs, and appropriate amounts of radiation to reduce host immune rejection. Xenogeneic animal tumor transplantation began in Leidy (1834), which is more difficult. In the past 50 years, the following methods are commonly used in allotransplantation: ① Inoculation under the skin or submucosa, the advantage is that it is easy to observe, but the rejection is large and the effect is poor. ②The animal tumor was transplanted into the chicken embryo allantoic membrane. The characteristic is that it is easier to survive, but human tumors have not been successfully reported. ③Human tumors are inoculated into the anterior chamber of rats, guinea pigs and rabbits. The disadvantage is that the cells cannot be passaged. ④ Transplant into animal brain. The tumor grows fast, but it is difficult and difficult to observe. In 1983, Badgen et al. used athymic rats to transplant human tumors under the renal capsule to screen new drugs. All experiments only took 11 days, and the hit rate was high. This work has brought good news to clinical patient drug screening.

　　Hundreds of transplantable human tumors have been established abroad since the 1960s. These tumor strains can prevent the formation and function degradation accompanying the passage. In 1969, Rygaaid successfully transferred human tumors to athymic nude mice for the first time, which opened up a new situation for xenogeneic animal tumor transplantation. Since nude mice lack T lymphocyte function, they are extremely ideal tumor transplantation model materials.