three months pass...
so there's a hormone called exendin-4 found in the saliva of gila monsters and it's being studied as a possible treatment for type-2 diabetes.
"The lizard eats only four times a year and turns its pancreas off the rest of the time. When it eats, it secretes exendin-4 to turn its pancreas on again ... exendin-4 acts by multiple mechanisms -- stimulation of insulin secretion, slowing gastric emptying, and inhibiting production of glucose by the liver. Furthermore, it seems to suppress appetite and promote weight loss."
(the research i'm citing is two years old; not sure what sort of progress has been made since.)
― monsanto and yanni (Jody Beth Rosen), Friday, 24 June 2005 08:18 (twenty years ago)
this article is from july 2004:
A few days ago, a good illustration of why we should try to conserve all living species - albeit for selfish reasons - was drawn to C-P's attention . A chemophiliac would recommend conservation on the grounds that organisms produce a diverse range of chemicals and at present, many, perhaps most, are unknown to us and could be of future value in medicine and other areas which would benefit humankind.
The organism referred to in a Cornell University magazine was the gila monster, a large, venomous lizard that lives in the deserts of Arizona and Mexico. It is an animal that only eats three or four meals a year, usually in the spring, and then converts much of the nutrients to fats (triglycerides) which are stored in its tail as an energy source for use during the rest of the year. The gila's meals are large and infrequent and the animal needs to ensure that the food is used efficiently and that it provides all the chemicals and energy that its cells need. One of the major organs involved in the utilisation of nutrients in vertebrates is the pancreas which produces hormones which regulate the processing of the food components. Two of these are insulin and glucagon which ensure that the level of glucose in the blood is kept within physiological limits and that body organs are properly supplied with this vital fuel and a source of building blocks for the cells. (A human body requires about 160g of glucose a day of which 120g are needed by the brain!).
The gila monster with its unusual eating habits has another mechanism to deal with nutrients - another hormone, exenatide, a peptide, which in response to eating, is synthesised in the small intestine, released into the blood and carried to the pancreas. Here it activates insulin production. This reduces blood glucose levels by encouraging the entry of the sugar into fat (adipose) and muscle cells to produce storage materials - triglycerides and glycogen, respectively. Insulin also induces some cells to break down glucose to CO2 and water with the release of energy.which can be used to 'power' the cell. The other pancreatic enzyme, glucagon, has the opposite effect to insulin; it raises blood glucose by a process called gluconeogenesis, an important mechanism to allow animals to resist starvation. It is achieved mainly by the conversion of 'non-carbohydrates' such as some amino acids and components of fats, to glucose. The production of glucagon is inhibited by exenatide. After the gila has eaten, the exenatide level is reduced and the pancreas returns to its original state.
Exenatide was first detected in the gila monster's saliva from where it was characterised and then a synthetic form (exendin) was made. With properties similar to exenatide, the synthetic peptide is being examined as a possible treatment for human type 2 diabetes (maturity-onset diabetes) As the name implies, this is a disease which is usually associated with older generations who are often obese. However, children are now developing the disease which, again, is thought to be associated with early obesity. Type 2 diabetics suffer from high blood glucose levels initially as a result of failure to respond properly to their insulin (insulin resistance) which is at normal levels. At this stage this can often be controlled by dieting or oral administration of drugs such as metformin. The disease can progress to a stage where blood insulin levels become too low (as in the case of type 1 diabetics who usually develop the condition early in life) in which case insulin injections are required or, hopefully, in the future, exendin may be helpful. Poorly controlled diabetes can lead to complications such as heart disease, blindness and poor blood circulation, particularly in the legs.
― monsanto and yanni (Jody Beth Rosen), Friday, 24 June 2005 08:27 (twenty years ago)