People often ask me what reptiles are good for, especially the venomous ones like rattlesnakes. Besides being an important part of the ecosystem and controlling rodents that spread diseases to people, several very interesting drugs have been developed from reptilian venoms. Venoms are known to affect the nervous or circulatory systems, and these properties have been exploited to produce effective treatments. Let me introduce you to four of them.
First is Captopril, an ACE inhibitor (angiotensin converting enzyme), that was approved by the FDA in 1981. This drug acts through vasodilation to reduce hypertension, treating congestive heart failure after myocardial infarction and preservation of kidney function in diabetic nephropathy.
Captopril is based on a protein found to be a peptide in the Lancehead Viper (Bothrops jararaca),
Next is a drug that was developed from one of my favorite venomous snakes, the rattlesnake. Rattlesnake venoms have components that affect their prey in different ways. One way causes anticoagulation, and the victim bleeds to death. The anticoagulating properties of the venom from the Southeastern Pygmy Rattlesnake (Sistrurus miliarius barbouri) led to the drug Eptifibatide. Eptifibatide is used for anti-coagulation therapies to reduce the risk of heart attacks. However this drug is only used in severe cases, because of the possible side effect of thrombocytopenia, a condition where platelets are unable to aggregate at all.
Courtesy of www.animalresearch.info
The third drug derived from reptiles is Exenatide, one of my favorite venom drugs. It is a synthetic version of Exendin-4, which is found in the saliva of Gila monsters (Heloderma suspectum), one of my favorite lizards. Gila monsters are not only colorful, they are the only venomous lizard in North America.
Exenatide is used to treat Type II Diabetes. It works by stimulating the pancreas to release more insulin for the control of blood sugar levels. Its molecular formula is C184H282N50O60S.
With this fourth drug, we are back to snakes. Hemolytic venoms from South American pit vipers, Bothrops atrox and Bothrops moojeni, produced Batroxobin. Batroxobin’s valuable action is to cleave or break up fibrinogen, similarly to similar to the effect of Thrombin. Thrombin’s action on fibrinogen creates fibrin, which is necessary for stopping the loss of blood as a result of injury. It’s the body’s bandage. The Batroxobin from B. atrox is called Reptilase and is used to stop bleeding. The B. moojeni version is used to break up clots as Defibrase. When used as part of Vivostat, baxotroxobin treats blood before surgery to produce clots. These clots are collected and then dissolved until a fibrin glue is created, that can then be used on the patient during surgery.
I hope you have enjoyed this post. We often dismiss animals we fear or don’t understand, not realizing their importance to their ecosystems and the environments we live in, and what they may offer to our lives, such as these important medicines.
To learn about the very interesting rattlesnake, in a vibrantly illustrated book written in rhyme (to make learning fun) please see my book, Don’t Make Me Rattle.
People fear rattlesnakes because they don’t understand them. Come inside and learn about these amazing snakes, how they help people, and why the rattlesnake should be respected, not exterminated.
Here at Lyric Power Publishing, science is very important–but we love to make science fun! We have developed wonderful, supplemental educational workbooks and activity sheets for children, to be used by teachers, parents and tutors. To learn about the fascinating and intelligent large lizards, the iguana, please see our workbook, My Unit Study on Iguanas.
To learn about the many differences between tortoises and turtles, please see the wonderfully illustrated and written in rhyme, Don’t Call Me Turtle!