Жыланның Deinagkistrodon туысы және оның сипаттамасы

Genus of snakes

Deinagkistrodon is a monotypic genus created for the venomous pit viper species, Deinagkistrodon acutus, which is endemic to Southeast Asia.

Deinagkistrodon acutus is light brown or greyish brown dorsally, with a series of dark brown lateral triangles on each side. The two pointed tops of the two opposite triangles meet each other at the mid line, forming a series of about 20 light brown, squarish blotches on the back. A row of large black spots extends along each side near the belly. The top and upper sides of the head are uniformly black, with a black streak from the eye to the angle of the mouth. D. acutus is yellowish ventrally, spotted with dark brown. The young are much lighter than the adults with essentially the same pattern. The head is large, triangular, with an upturned snout. The body is very stout. The tail is short, ending in a compressed, pointed slightly curved cornified scale. The top of the head is covered with nine large shields. The dorsal scales are strongly and tubercularly keeled. The subcaudals are mostly in pairs, some of the anterior ones are single. This stout snake, usually between in total length (including tail), reaches a maximum total length of in males and in females. The largest specimen on record measured approximately .

Common names for D. acutus include sharp nosed viper, snorkel viper, hundred pacer, Chinese moccasin, Chinese copperhead, five pacer, hundred pace snake, long nosed pit viper, sharp nosed pit viper, hundred pace pit viper. The snake has been an object of veneration by indigenous Taiwanese peoples.

Deinagkistrodon acutus is found in southern China (Zhejiang, Fujian, Hunan, Hubei, Guangdong), Taiwan, northern Vietnam, and possibly Laos. The type locality was not included in the original description. It was later given as "Wusueh [Wuxue], Hupeh [Hubei] Province, China" by Pratt (1892) and Pope (1935). Listed as "Mountains N. of Kiu Kiang [Jiujiang]" in the catalogue of the British Museum of Natural History. Brown (1973) mentions a venom yield of up to 214 mg (dried) and (toxicity) values of 0.04 mg/kg IV, 4.0 mg/kg IP and 9.2–10.0 mg/kg SC. The venom contains at least four hemorrhagins Acutolysin A, B, C and D.

According to the US Armed Forces Pest Management Board, the venom is a potent hemotoxin that is strongly hemorrhagic. Bite symptoms include severe local pain and bleeding that may begin almost immediately. This is followed by considerable swelling, blistering, necrosis, and ulceration. Systemic symptoms, which often include heart palpitations, may occur suddenly and relatively soon after the bite. If injected into mice, within 2 hours the venom begins a process known as mesangiolysis (the degeneration and death of cells that line the inner layer of the glomerulus and regulate glomerular filtration in the kidney). When controlled, the venom has some clinical application. D. acutus snake venom contains a protein called ACTX 6. This protein was shown to induce apoptosis (cell death) in isolated cancer cells through Fas pathway activation. This pathway is made up of a series of proteins called initiator and executioner caspases. Initiator caspases help form an apoptosis initiation factor that eventually activates executioner caspases (see figure 3). Executioner caspases go on to "digest" the cell from the inside out. They cleave cytoskeleton filaments and DNA until the cell completely implodes. Different parts of the snake are also prescribed to help alleviate ailments known as "wind diseases". The same qualities that make snakes flexible, capable of regenerating skin, and able to inflict paralysis could be transferred to human conditions if applied medicinally. The vipers are prepared by cooking the flesh of the headless body, grinding a paste of snake ash and mixing it with honey, drying the snake and compacting it into a powder, or even injecting their venom intravenously. Although these practices are common in Chinese medicine, no current studies have affirmed the effectiveness of these treatments. Whether these "cures" simply have a placebo effect or actually heal the patients is not known.