The treatment of "blood stasis" and "water stagnation" shows its unique curative effect. Zhang Xichun praised this medicine in the later generations: "Blood stasis does not hurt new blood, it is a good medicine, pure as water, but qi is not damaged at all, while blood stasis is invisible." Before 1500, the Egyptians began bloodletting therapy with medical leeches. By the beginning of last century, Europeans were more superstitious that medical leeches could suck sick blood from human body, and they used medical leeches for blood-sucking treatment regardless of headache and brain fever. Later, with the development of medicine, this superstitious treatment method was gradually abandoned. However, in recent years, the new use of medical leeches in medicine has been widely concerned. Plastic surgeons use medical leeches to eliminate congestion and reduce necrosis in the vascular occlusion area after operation, thus improving the success rate of tissue transplantation and breast formation. When medical leeches are replanted or transplanted to fingers, toes, ears and nose, using medical leeches to suck blood can make veins unobstructed and greatly improve the success rate of surgery. This is because the salivary glands of medical leeches secrete anticoagulant hirudin and histamine-like substances that dilate blood vessels when sucking blood. 65438-0987 Leech Research Group of Institute of Aquatic Animals of China Academy of Sciences cooperated with Orthopedics Department of the Third Affiliated Hospital of Hubei Medical University. Medical leeches were first used in China to treat blood stasis after replantation of severed fingers, and several cases were successful, which was widely praised at home and abroad. A variety of active substances contained in the saliva of medical leeches are attracting wide attention from scientists all over the world and have become a hot spot for the utilization of resource animals. From 65438 to 0984, Dr. Sawyer, an American leech expert, founded the world's first leech farm and biochemical drugs Company in Sethi, Wales, England. Hirudin and hyaluronidase produced by this company have been sold to European and American countries and Japan, and tens of thousands of live medical leeches have also been sold. Recently, a medical leech farm was built in Charleston, USA. France and Germany have transferred the gene for synthesizing hirudin into yeast and Escherichia coli, and produced cheap hirudin through genetic engineering. It can be seen that the demand and output of hirudin are expanding. Hirudin is a low molecular weight (7000) polypeptide composed of 65 amino acids, in which glutamine and asparagine have higher molecular weight and lower isoelectric point (3.8 ~ 4.0), and are stable for a long time at room temperature. Hirudin is the most effective natural anticoagulant known, superior to heparin, and has anticoagulant and thrombolytic effects, that is, the function of promoting blood circulation and removing blood stasis in traditional Chinese medicine. Therefore, it shows great advantages and broad prospects in the treatment of septic shock, atherosclerosis, cerebral infarction, cardiovascular diseases, hypertension, ophthalmology and many other diseases lacking antithrombin.
Edit the medical function of this paragraph.
Hirudin in the salivary gland of fresh leech contains protein, and protein is a polypeptide composed of various amino acids, including aspartic acid 10, glutamic acid 13, cysteine 6, serine 4, glycine 9, threonine 4, alanine 1, valine 3, leucine 4, isoleucine 2, proline 3 and phenylalanine. Pure product is gray or white scale or powder, acidic, soluble in water, physiological saline and pyridine, insoluble in ethanol, acetone and benzene, and easy to deteriorate when heated or in dilute acid. Hirudin in dried medicinal materials has been destroyed. In addition, it also contains heparin. Antithrombin. Research progress of chemical constituents: physical and chemical identification, pharmacological action, 1. Anticoagulant effect: 0.45g/kg leech water extract can significantly inhibit ADP-induced platelet aggregation in rats, reduce the specific viscosity of whole blood and plasma, and shorten the erythrocyte electrophoresis time; In vitro experiments showed that leech water extracts of 200mg/ml, 100mg/ml and 50mg/ml also had obvious inhibitory effects on platelet aggregation in healthy people. Hirudin can prevent thrombosis caused by bacterial endotoxin in rats and reduce the mortality of rats. Hirudin can also resist thrombin-induced contraction of isolated frog hearts. 2. Improve microcirculation: Intravenous injection of leech injection 2g/kg can promote the absorption of hematoma in experimental acute cerebral hemorrhage in rabbits, reduce the inflammatory reaction and edema around brain tissue, relieve the increase of intracranial pressure, improve local circulation, and be beneficial to the recovery of neurological function; It can also promote the absorption of local experimental hematoma in rabbit ears. 3. Anti-early pregnancy effect: subcutaneous injection of 40% Hirudo decoction for 2 days can terminate pregnancy in mice at all stages, including implantation, early, middle and late stages, but early pregnancy has the best effect; If exogenous progesterone is injected with leech at the same time, it can antagonize leech's anti-early pregnancy effect.