动物造模,高血压动物模型 z-bio 2021-11-04 289

　　1. Overview of neurological and spiritual causes of hypertension

　　In the pathogenesis of hypertension, genetics and environment are the two main influencing factors. Many researchers believe that although genetic predisposition can determine whether or not to develop hypertension, environmental factors ultimately determine the level of elevated blood pressure. Nervous, mental, and emotional factors are considered to be the main environmental factors, including long-term psychological and behavioral stress stimulation, which promote the occurrence and development of hypertension. Yang Jun and other 12 patients with traumatic lower extremity deformities measured blood pressure, heart rate, and respiratory rate three days before surgery and before anesthesia. At the same time, radioimmunoassay was used to determine the levels of arginine vasopressin (AVP) in plasma and cerebrospinal fluid. content. The results showed that systolic blood pressure and diastolic blood pressure increased significantly after anesthesia, heart rate increased significantly, plasma AVP content decreased, and AVP in cerebrospinal fluid increased. The Christina M study considered demographic distribution, age, smoking status, and body mass index, and found that people with depressive symptoms are at higher risk of developing hypertension in the next 20 years, and those with severe depression have shorter years of hypertension. After 20 years of follow-up of 1123 patients with normal blood pressure, Markovit et al. found that in middle-aged men, anxiety and panic attacks, anger, and suppression of emotional vent after anger can significantly increase the percentage of hypertension, which is the occurrence of primary hypertension. A predictor of development.

　　The current research results believe that long-term psychological stimulation activates the hypothalamic-pituitary-adrenal cortex axis. Elevated corticosteroids in turn activate the sympathetic system, through the central regulatory mechanism, aggravate the excessive activation of neurohumoral factors, leading to the release of catecholamines and peptides in the plasma, and at the same time accelerate the damage of vascular endothelial cells, leading to vasoconstriction , Platelets are activated, and the heart rate increases. All these have exacerbated the damage to the cardiovascular system. Accelerate the occurrence and development of hypertension.

　　In order to fully study the influence of neuropsychiatric factors on the mechanism of hypertension. Many scholars at home and abroad use different stimulation techniques to prepare models of neuropsychiatric hypertension in order to more fully relieve the genetic factors, neuropsychiatric factors play a role in the occurrence and development of hypertension.

　　2. Preparation of animal model

　　The commonly used methods of making molds are as follows:

　　1. Forced swim animal model (forced swim test) is a model designed by using animals that cannot escape from the harsh environment, resulting in desperate behavior. Suitable for rats or mice.

　　The method of making a forced swimming animal model: Each laboratory has different specific methods and facilities due to different experimental purposes, but the conventional method of copying the model is as follows:

　　(1) Swimming experiment

　　1) Place the replicated model animals (large and mouse) in a transparent glass cylinder for swimming experiments.

　　2) One per tank, with varying depths of water (note the depth of the water to prevent the front and hind limbs of rats and mice from touching the bottom surface and supporting their bodies in the water).

　　3) The water temperature varies from 22 to 29°C. After each test, the water in the tank needs to be drained and cleaned before starting the next test.

　　In the experiment, rats and mice will change their behaviors after struggling for a period of time, that is, change from a positive state to a negative state (only maintain the minimal movement posture with the head above the water), and at the same time repeat the forced swimming experiment The immobility time also gradually increased.

　　(2) Weight-bearing swimming: The weight-bearing swimming model adopted by the Peking University Medical Department. After the rats and mice are weighed, a lead skin of 3% to 5% of their body weight is tied to the tail. After the animal is loaded, the swimming movement is obviously imbalanced. Can't hold on anymore. You can't return to the surface by yourself after submerging for 10 seconds.

　　2. The tail suspension test is mostly applicable to mice. The tail of the mouse is fixed on a wooden stick or iron rod with tape or string, preferably at the root of the tail, to prevent the mouse from tearing the tail when it is struggling. The mice began to struggle violently, and over time, they were in a desperate suspension state.

　　3. Restraint experiment You can buy restraint clips to fix it. Or as shown in Figure 8-2 (Method of Modeling in the Hypertension Research Laboratory of Peking University People’s Hospital): Choose a bottle of an appropriate size, open the front to ensure that the animal breathes, and the body in the container should not turn back and forth, and the tail is fixed. Chained in a container. The binding time varies (may be 1-12 hours). Acute restraint can successfully induce experimental anxiety, while chronic restraint is a chronic irritable stress response. This model has less physical stress factors and can better highlight psychological or emotional factors. Suitable for rats and mice.

　　4. Electric shock to the sole of the foot Put the animal in the compartment of the plantar stimulator, and shock the sole of the foot with low-frequency and low-voltage alternating current. The animal appears to quickly escape, scream, and erect its tail. During stimulation, the current intensity should be gradually increased according to the animal's response, and it is advisable not to burn the sole of the animal to cause an escape response.

　　5. Water-free, fasting, tail-clamping and intermittent lighting experiments

　　(1) Water forbidden experiment: Water forbidden for 12 to 24 hours.

　　(2) Fasting: ranging from 12 to 24 hours.

　　(3) Clip the tail: 1 minute.

　　(4) Intermittent light: 2 hours of light and 2 hours of darkness alternate for 12 hours, turning day and night upside down for 24 hours, empty bottle stimulation and noise interference, humid environment, crowded environment (5-6 rats are placed in a volume of 25cm×40cm× 15cm feeding box).

　　Because of the different experimental designs, researchers in various countries often use one or two stimulation methods to make models. In order to better simulate the human psychological stress response, some scholars have adopted multiple compound stress methods in recent years. The chronic mild stress model falls into this category. Chronic mild stress includes a series of unpredictable low-intensity stresses, such as restraint, forced swimming, water cut, crowding, etc. One to two stimuli are used daily, and each stimulus is used 5-7 times on average. The same stimulus Can not appear continuously, so that rats can not predict the occurrence of stimulation. From the perspective of etiology, the environmental inducements of mental behavioral stress are simulated, and changes in brain and kidney neurotransmitters, plasma hormone levels, and blood pressure and heart rate are observed. Provide a theoretical basis for further research on neuropsychiatric hypertension.

　　The above are all stimulation methods that simulate the increase in blood pressure caused by common mental stress in humans.

　　3. The purpose of model establishment

　　The establishment of this model is of great value for understanding the causes and risk factors of hypertension. It is highly praised by domestic and foreign scholars. This type of hypertension has the following similarities with human hypertension: the blood pressure fluctuates greatly in the early stage of hypertension, and then gradually rises and remains at a high level. Environmental and stressful stimuli cause a significant increase in blood pressure, and high-level nerve activity disorders appear during the development of hypertension. The content of catecholamines in the blood of some animals increased.

　　4. Solve scientific problems in experiments

　　Genetic and environmental factors play an important role in the pathogenesis of hypertension. In 1960, Japan successfully bred a model of hereditary hypertensive rats (SHR). The research on hypertension caused by genetic factors has developed rapidly. Various theories are relatively complete at present. The research on neurological hypertension caused by environmental stimuli differs depending on the type of stressor, animal species, gender, physiological state, and stress state, and even the opposite conclusions are reached in some experiments. The nervous system, endocrine system and immune system involved in stress are a whole, and the details related to the onset of hypertension are the focus of in-depth research.

　　V. Research progress and evaluation of animal models

　　(1) Related research progress of the corresponding animal models of hypertension (review of experiments done by different basic research institutes in the past 5 years) Various psychological stress models can be directly through the central nervous system, sympathetic nervous system, neuroendocrine system, etc. And indirectly affect the content of serum catecholamines and glucocorticoids and the expression, release and distribution of various other hormones, transmitters, cytokines, neuropeptides and other substances. Regulate changes in blood pressure and heart rate. The results obtained by different stress methods are very different.

　　(2) The clinical response of an animal model using electrical stimulation. The Hypertension Research Laboratory of Fuwai Cardiovascular Hospital used ringtones (with varying stimulation durations) and electrical stimulation (10-15V, 5 seconds) to conduct experiments on 12 dogs. There are 11 dogs with elevated blood pressure, and there are obvious individual differences in the duration of hypertension and the degree of blood pressure increase. Sohn HS performed chronic stress stimulation on SHR and WKY. Comparisons found that the hypothalamic-pituitary-adrenal cortex axis and sympathetic system of SHR increased, and putrescine levels also increased, all of which promoted the increase of SHR blood pressure. In subsequent studies, no continuous changes in autonomic nervous system activity were found, but vascular resistance increased.

　　Sandra Cordellini performed restraint and swimming stress stimulation on SHR and WKY, and found that the thoracic aorta weakened response to norepinephrine after stress stimulation, and the vascular endothelial function was impaired. Stamp and Herbert performed a 14-day restraint test on rats. As a result, the heart rate increased and the peripheral resistance did not change significantly. The reason for the analysis may be the self-adjustment process of rats.

　　(3) The clinical response of restraint stress McDougall SJ used restraint stress method to stimulate hypertensive rats and normal blood pressure rats, and used autoradiography to find vasopressin V and angiotensin receptor I in brain and kidney , The density of angiotensin receptor II changes. Rönan Duncko applied chronic mild stress stimulation and found changes in the expression of TH gene in the adrenal glands. They concluded that this could be a predictor of cardiovascular disease in depressed patients. Lawler and Edgemon conducted a restraint stress study on borderline hypertensive rats with genetic predisposition and found that stimulation for 5 to 16 weeks was accompanied by an increase in salt consumption.

　　Lane et al. reported that after behavioral stimulation, due to higher parasympathetic tension, heart rate can adapt faster than blood pressure changes. It is believed that the increased parasympathetic nerve activity counteracts the effect of sympathetic nerves on the heart. They believe that the effects of sympathetic and parasympathetic effects may act on a particular organ, rather than the whole body system. Different stimulation methods have different effects on heart rate and blood pressure. For example, for SD rats, electric shocks to the soles of the feet increase blood pressure and heart rate. Restraint stimulation only raises the heart rate and has no effect on blood pressure.

　　Animal gender differences also have different responses to chronic stress. Baker S performed chronic mild stress stimulation on rats and found that female rats were more sensitive to the stimulation.

　　6. Evaluation characteristics of antihypertensive drugs in experimental models

　　Fuwai Cardiovascular Hospital studied the effects of reserpine on blood pressure, heart rate, high-level nerve activity and blood catecholamine levels during the formation of neurogenic hypertension. 10 healthy adult dogs were randomly divided into two groups, a control group, a group of oral reserpine (reserpine 0.05 mg/kg per day during the first and second stage stimulation 14 days before the stimulation period), the third stage Stop taking reserpine during the stimulation period. The control group did not take any drugs. The stimuli given to the two groups of animals were the same. The results show that although reserpine has a hypotensive effect, it cannot prevent the increase in blood pressure during stimulation. Since the stress stimulation methods used are mostly used in the study of abnormal mental behavior, most of the research focuses on the study of abnormal blood vessel function and the physiological regulation mechanism of the brain and kidney. Coupled with the differences in the stress methods adopted by each. At present, laboratory studies on the treatment of neuropsychiatric hypertension with antihypertensive drugs are rare at home and abroad.

　　In clinical studies, early Pandhi P applied drug therapy in 7 patients with elevated blood pressure caused by stress and found that the combination of alpha blockers and beta blockers can reduce stress better than single drugs. The resulting increase in blood pressure. Malhotra S studies the effect of calcium antagonists on stress-induced increase in blood pressure. The results of a randomized, double-blind study showed that cold stress and grip strength experiments can increase blood pressure in subjects with normal blood pressure, but amlodipine and lacidipine can stimulate Increased blood pressure has no effect. Sosner P also reported that calcium antagonists, converting enzyme inhibitors, moxonidine, and β-receptor blockers have no hypotensive effect on stress-induced increase in blood pressure. However, the Kahan T study found that ramipril can reduce the stress load of the heart under stress conditions. However, the disadvantage of the above-mentioned research is that the selected sample size is small. It is difficult to observe a significant effect.

　　Because the intensity and characteristics of stress depend on the individual's evaluation of the environment or information and the emotional response caused by it. Therefore, there are great difficulties in the design and evaluation of animal models. For the study of antihypertensive drugs for stress-induced hypertension, a large number of animal experiments are still needed for theoretical support.