生物谷报道：在英国，约有两百万人饱受糖尿病所苦；尚有约50万人并未诊断出胰岛素失衡。据统计，这项疾病使英国男性平均年龄下降有五岁、女性达七岁之多。此外，糖尿病除了无法正常调控血糖的升降外，常伴有心脏疾病、肾脏衰败与夜盲，甚至因感觉迟钝而容易导致感染与伤口溃烂，进而需要截肢。
现在，由生长在美国西南部和墨西哥沙漠的希拉毒蜥（Gila monster）唾液中所发现一个类荷尔蒙成分exendin-4，经由实验证实能够有效帮助糖尿病换回复胰岛素的分泌。
在健康的人类个体中，GLP-1会在血糖过高时，刺激腺制造胰岛素制造与分泌。 在第二型糖尿病的患者中，此调控路径由于讯息过弱而无法正常调控血糖。以“Exenatide”为产品名称正式上市的药物，与人类血液中调控血糖激素“胰高血糖激素胜肽1（glucagon-like-peptide-1，GLP-1）”的相仿，能够帮助46％的患者在投药后恢复正常的胰岛素调控状态。
希拉毒蜥仅三年到四年觅食一次，正是其唾腺中的exendin-4成分帮助它缓慢而稳定的维持一定的消化速度。“这给我们应用在糖尿病治疗的灵感；”礼来制药公司（Eli Lilly）的Michael Trautmann博士表示：“Exenatide的发现让我们清楚的了解，在人类血糖代谢机制上如何以新的方向去调控。”
相关英文原文：
Saliva of monster Mexican lizard providing lifeline to type 2 diabetes
By JENNY HOPE - More by this author » Last updated at 22:00pm on 7th May 2007
A 'monster' lizard from Mexico could hold the key to providing a better life for people with type 2 diabetes.
The two-foot-long pink and black lizard called the Gila monster has inspired the development of a new drug to tackle the disorder.
Scientists have isolated a chemical in its saliva which is similar to a human hormone that helps regulate blood sugar.
The garish Gila monster only eats three or four times a year but the compound known as exendin-4 produced in its salivary glands helps them digest these meals very slowly.
This unique quality has now been copied and produced synthetically in the injectable drug exenatide.
Exenatide - the first in a new class of medicines known as incretin mimetics - works by stimulating the pancreas to produce more insulin in response to raised blood sugar, and also influences digestion and appetite.
The Gila monster also happens to be one of only two venomous lizards in the world - but scientists wanted to analyse its spit, rather than the poison produced by glands in the lower jaw.
Although this is capable of killing its prey of small mammals and birds, humans are unlikely to get more than an irritating bite.
The drug companies Eli Lilly and Amylin Pharmaceuticals are now launching exenatide under the brand name Byetta.
Dr Michael Trautmann, from Eli Lilly, said exendin-4, found in the lizard's saliva, acts in a similar way to the human hormone glucagon-like-peptide-1 (GLP-1).
In healthy humans, GLP-1 stimulates beta cells in the pancreas to produce insulin when blood sugar levels get too high.
But in type 2 diabetics, the GLP-1 message system can break down because the signal to make more insulin is weak or missing.
Dr Trautmann said "The development of exenatide is an excellent example of how greater understanding of the physiology of humans can lead to innovative treatment discoveries.
"The GLP-1 mechanism plays an important role as an incretin in regulating blood glucose, intestinal food absorption, and appetite.
"The Gila monster only eats three or four times a year, and a compound produced in its salivary glands called exendin-4 may help them digest these meals very slowly over time.
"That is an advantageous quality when translated into controlling diabetes."
Wild populations of the Gila monster and its equally poisonous cousin the Beaded Lizard are declining rapidly due to habitat loss and illegal hunting for the pet trade.
This has led conservationists to set up Project Heloderma in central and north America, where the reptiles live.
In recognition of the Gila monster's gift to medicine, Eli Lilly is making a charitable contribution to the project over the next three years.
Richard Gibson, Curator of Herpetology at the Zoological Society of London, said "The Gila Monster is an amazing reptile and one without which this valuable discovery would not have been made.
"Worryingly, both the Gila Monster and its close relative, the Beaded Lizard, are under serious threat, a situation that Project Heloderma is trying to address.
"I hope that further awareness of its role in this exciting medication will highlight the importance of preserving the habitat of Gila Monsters and related species."
Cathy Moulton, care adviser at Diabetes UK charity, said "Managing blood glucose levels along qwith blood pressure levels is central to reducing the risk of heart attacks, blindness, strokes, kidney disease and amputations in people with type 2 diabetes.
"This is an exciting time as any new treatment that helps people with type 2 diabetes that is safe and effectige is to be welcomed.
"New treatments provide more options to ensure the most effective treatment for any individual."
