Clenbuterol, also known as clenbuterol hydrochloride, clenbuterol, clenbuterol, as the name implies, is a drug that can be used to improve the leanness of meat, its scientific name is “clenbutero hydrochloride (CLB)”, chemical name “2-“(tert-butylamino)methyl”-4-amino-3,5-dichlorobenzyl alcohol hydrochloride”, molecular weight: C12H18 Cl2N2O HCl, molecular weight 313.65, is a synthetic derived from natural catecholamines. The chemical name is “2-(tert-butylamino)methyl”-4-amino-3,5-dichlorobenzyl alcohol hydrochloride”, molecular formula: C12H18 Cl2N2O HCl, molecular weight 313.65, is a kind of compound derived from natural catecholamine synthesis, was named aminoglutethimide, ketorol and other asthma medicine of the main ingredients, it is a white or similar white crystalline powder, odorless It is a white or white-like crystalline powder, odorless, slightly bitter, chemically stable, and can only be decomposed when heated to 172 degrees Celsius (5 min of oil frying at 126 degrees Celsius will halve the damage). Therefore, the general cooking and heating method can not destroy the residual toxicity of “lean meat essence” in pork and organs. Used as a feed additive, its main mechanism of action is as a strong agonist, selective action on the adrenergic receptors, activating adenylate cyclase (cAMP), so that the increase in cyclic adenosine, enhance fat decomposition, promote protein synthesis, to achieve animal nutrient redistribution, so leptin is also called “growth promoter ( growthpromotef)” and nutritional “redistribution agent (partitioning agent)”. A, leptin (clenbuterol) toxic effects leptin (clenbuterol hydrochloride) as a strong selective β-2 agonist, its relaxation of bronchial smooth muscle effect is strong and long-lasting, so that bronchial diastole, ventilation improvement, uterine smooth muscle also showed diastole, relaxation, can strongly affect the body’s material metabolism, reduce lipogenesis and promote lipolysis, promote protein synthesis, so that degradation is reduced; also can It also promotes the release of insulin and increases the breakdown of glycogen, which results in an increase in the concentration of free fatty acids, lactic acid and glucose in the blood. Clenbuterol hydrochloride is rapidly absorbed after internal administration and has a cumulative effect, with a half-life of 0.22h in pigs. 5ug/kg in calves, plasma concentration increases continuously after 20min and reaches a peak in 2-7h. The distribution of the concentration in the experimental mice was in the following order: adrenal gland, kidney, pancreas, lung, bone marrow, liver, heart muscle, muscle and brain. After internal administration, it was metabolized in the gastrointestinal tract and the liver, and several metabolites were produced. The bioavailability in pigs is 61.2%, and a large amount is excreted in the urine in its original form, with urinary concentrations 40 times higher than blood concentrations. When clenbuterol hydrochloride is used as an accelerated growth regulator, the dose is more than 10 times the normal treatment for asthma. When used as a growth promoter and redistributor, the dose is higher (5 to 10 therapeutic doses) and the duration of use is longer (generally more than 3 weeks of continuous use), and the animal is prone to side effects after use. If there is no rest period before slaughter, there will be higher residual concentrations in muscle and internal organs, and they will not be easily destroyed (172℃ for 1h to be destroyed). The highest residual concentration is in the eye tissue, which is 107 times higher than the plasma concentration (1.1ng/mg), and the residues in other organs are: lung, liver and kidney are about 20-90 times of the plasma concentration, and muscle and fat are 3-15 times. When people consume more than 100g of animal lung or liver, they will get the same amount of clenbuterol as the treatment dose, which is slowly eliminated in the body and mainly accumulates in the internal organs, hair, retina and other tissues. Long-term consumption of pork and offal containing “lean meat extract” can cause diseases of the human cardiovascular system and nervous system. If pork containing “lean meat essence” is consumed by humans, the toxic reaction dose varies from person to person when humans consume animal products with residual “lean meat essence”. The symptoms usually appear in 15min~6h and last for 90min~6d. They are usually flushed, headache, chest tightness, palpitation, panic, skeletal muscle tremor, numbness of limbs and a series of other adverse reactions. Second, the discovery and application of leptin In the early 1980s, the U.S. Lipoamines researchers accidentally found that a certain amount of clenbuterol hydrochloride added to the feed, can change the metabolic pathway of nutrients to promote animal muscle, especially skeletal muscle protein synthesis, while having a certain inhibitory effect on fat synthesis, which can promote animal growth and increase the lean meat rate, and according to certain tests If you add the right amount of clenbuterol hydrochloride to the feed, you can improve the feed conversion rate, growth rate, improve the lean meat rate of more than 10%. So, at that time, this is considered a rare feed drug additive, and the promotion of applications around the world, and China also in the late 1980s, in some universities and colleges, research institutes to carry out research and development tests and promotion tests, after proving that its effect is very obvious, and clenbuterol hydrochloride referred to as lean meat essence. Although this feed additive has not been recognized by the competent state departments, but driven by the interests of many regions of China’s feed processing enterprises and farmers have begun to promote the application. Third, the first case of leptin poisoning caused by its poisoning occurred in Spain, it is reported that in 1990, Spain, 43 families 135 people suffered from food poisoning after eating beef liver fed leptin; and China’s earliest leptin poisoning occurred in Hong Kong, May 1998, Hong Kong, 17 residents were poisoned by eating pig offal supplied by the mainland, while Guangdong Province In a short period of time, there were seven cases of poisoning from drinking pig lung soup. Since then, incidents of poisoning due to consumption of animal products fed with lean meat extract have been reported one after another in the world. In China, on October 6, 1999, 57 people were poisoned in Jiaxing City, Zhejiang Province; on April 14, 2000, 30 people were poisoned in Longhua Town, Boluo County, Guangdong Province; on October 9, 2000, 57 people were poisoned in Hong Kong; and on November 7, 2001, 747 people were poisoned in a mass poisoning incident in Heyuan, Guangdong Province. This has caused people to study and pay attention to the toxicity of lean meat extract. Fourth, lean meat extract poisoning symptoms: Incubation period: “lean meat extract” poisoning incubation period is generally short, the shortest for 30min, the longest can be lOh, the average 1-2h or so. The average onset time of 76 cases of “lean meat extract” poisoning was 2.5±1.5 hours according to Wang Lei [76 cases of “lean meat extract” poisoning clinical report], and 1047 cases of acute lean meat extract poisoning were observed by Liu Huanqing, who found that the earliest clinical symptoms appeared 25 minutes after the meal [acute Analysis of 1047 cases of leptin poisoning]. The main clinical features: fast heart rate, the fastest is 135 times/rain, generally about 120 times/min; dizziness, nausea, weakness of the limbs; muscle tremors in the fingers and arms, sometimes accompanied by vomiting, abdominal pain, flushing, and congestion in both eyes. At the beginning of the disease, dizziness, palpitations, chest tightness, weakness, muscle tremors of the limbs and twitching symptoms are more common, some patients can be accompanied by nausea, vomiting, slight blurring of vision and other symptoms, but there are no pupil changes. The poisoning of “lean meat extract” is not contagious, there is no obvious seasonality or locality, but there are familial or collective morbidity characteristics. Cardiovascular system: Stimulation of the heart: It has a great stimulating effect on the human heart, producing palpitations and panic, resulting in inadequate perfusion of blood to the heart muscle and myocardial damage. Effects on blood pressure: mainly through agonism of 2-receptors. It has an excitatory effect on the heart, making the heart positive phase change when the force, the heart ejection volume per minute increases, and blood pressure increases. Stimulation of the nervous system, resulting in nausea, vomiting, dizziness, weakness and muscle tremors, hand tremors and even inability to stand Effects on glucose metabolism, resulting in insufficient glycolysis in muscles, resulting in high pH V. Laboratory tests: 1. Biochemical index test: serum K+, CK and CK-MB are good monitoring indicators for patients with CLB poisoning. Serum potassium is reduced, and the results of creatine kinase (cK) and its isoenzyme (CK-MB) of myocardial enzyme spectrum are significantly increased. 2. ECG examination:: accelerated heart rate, premature ventricular boom, S-T segment depression and T-wave inversion, etc. 3, pathological histological examination people in the consumption of more than 100g of animal lungs or liver contaminated with “lean meat essence”, will get the same dose of clenbuterol, the drug in the body slowly eliminated, mainly accumulated in the internal organs, hair, retina and other tissues, long-term consumption of pork and offal containing “lean meat essence Long-term consumption of pork and offal containing “lean protein” can cause diseases of the human cardiovascular system and nervous system. Patients with cardiac arrhythmia, hypertension, glaucoma, diabetes, hyperthyroidism, prostate hypertrophy and other diseases can be more dangerous or even life-threatening. Animal experiments have observed that the main pathological manifestations of “lean protein” poisoning of the organs are heart, liver and kidney tissue degeneration, necrosis and inflammatory changes. (1) liver: light microscopy saw the appearance of central venous dilatation, lymphocytic infiltration in the confluent area, hepatocytes watery degeneration, partial necrosis. (2) Kidney: light microscopy showed aqueous degeneration of tubular epithelial cells in the medulla, focal necrosis, and interstitial and glomerular lymphocytic infiltration. (3) heart: light microscopy can be seen under the dilated blood vessels, congestion, focal lymphocyte infiltration, focal myocyte degeneration necrosis. Six, “lean meat essence” detection method research progress At present, the detection of lean meat essence, there are four main methods, namely, high performance liquid chromatography (HPLC), gas chromatography and mass spectrometry (GC-MS), capillary zone electrophoresis (CE) and immunoassay technology (IA). And China combined with its own actual situation, in 2001 the Ministry of Agriculture first organized the development of the determination of clenbuterol hydrochloride in feed standards. The standard chose to identify two kinds: namely, high performance liquid chromatography (HPLC), gas chromatography a mass spectrometry (GC-MS). The HPLC method as a semi-confirmative method for the detection of lean meat, the minimum detection limit of 0.05 μg/kg, the advantage of high detection accuracy, and low false positive rate; disadvantage is the detection process is cumbersome, long detection time, the need for expensive instruments, difficult to operate, expensive. The GC-MS method has the advantage of qualitative and quantitative analysis of a specific residue in the presence of multiple residues at the same time. The disadvantages of the GC-MS method are similar to those of HPLC. At present, the British Randox Labotories litd and Germany’s R-biopharm companies have developed ELISA kits for the detection of lean meat, feed. Seven, leptin (clenbuterol) poisoning diagnosis: clenbuterol (leptin) poisoning is the most reliable diagnostic indicators of the poisoned person’s blood, urine and into the poultry animal tissue clenbuterol (leptin) content detection, but the poisoned person’s blood, urine and into the animal tissue in the clenbuterol to be detected with a high degree of accuracy of the instrument. The instruments used in general hospital laboratories are not yet able to meet this requirement: at present, there are not many domestic instruments that can detect, even in Beijing, can be carried out in meat “lean meat essence detection units are limited to the Ministry of Agriculture and a few research units. Therefore, the clinical diagnosis mainly relies on the poisoned person has a history of eating animal offal or meat, especially after eating animal liver, lungs, kidneys and other organs, dizziness, headache, nausea, vomiting, panic, palpitations, muscle tremors, trembling and other symptoms, should be highly alert to “lean meat extract” poisoning, when the diagnosis can not be determined. Specimens can be collected and sent to the unit with the above equipment for toxicological analysis and identification. Eight, leptin poisoning treatment: leptin (clenbuterol) poisoning no specific treatment measures, the current main line of symptomatic support treatment. 1, the early poisoning can be given gastric lavage, diarrhea; for the drug has been absorbed into the blood, to take intensive diuretic method to accelerate drug clearance: eating animal meat or offal containing clenbuterol (leptin) poisoning symptoms are mild, give general sedation can control symptoms. 2. Seriously ill patients are placed in the intensive care unit for 24 h cardiac monitoring and need to be treated according to the symptoms of poisoning and according to the principles of treatment of related organ damage. For example, anticonvulsant diazepam can be given for convulsions; appropriate antihypertensive drugs can be given for high blood pressure, and if necessary, drugs with rapid action and adjustable administration speed such as sodium nitroprusside can be given; β-one receptor blocker can be applied for tachyarrhythmia, such as esmolol (esmolo1) 50-150ug/kg intravenous drip, while hypertension is given for the first time 300ug/kg intravenous drip for 1min, and then 50ug/kg every minute to maintain; etc. 3, immediate infusion, potassium supplementation, correction of water, electrolytes, acid-base balance. Give Astragalus, raw vein and other drugs intravenous drip to nourish the heart and blood vessels and oral vitamin C, vitamin B6.