Sheep as models for diabetes

Flock of sheep.jpg Image of sheep from Wikimedia Commons

Insulin is a major hormone responsible for regulating blood sugar. Its main function is to lower sugar by increasing glucose uptake into muscle and fat cells. Insulin resistance is the hallmark of type 2 diabetes and occurs when tissues in the body are not able to respond to insulin resulting in sustained elevations in blood sugar, also known as hyperglycemia.

An alternative mechanism for lowering blood sugar is muscle contraction as it stimulates a pathway distinct from insulin in the muscles to cause glucose uptake from the blood. Exercise also helps to improve insulin sensitivity in muscles. Currently most research in this area focuses on laboratory rodents, which are rather short-lived in comparison to humans. Researchers at Victoria University and the University of Adelaide in Australia have shown that sheep may provide a good model in which to examine the effects of exercise in a longer lived mammal. Their findings were published recently in the American Journal of Physiology - Regulatory, Integrative and Comparative Physiology. Using larger mammals overcomes the limitations of small sample sizes from rodent studies and opens the door for studies that are not possible to conduct using humans.

What they found was that treadmill exercise (30 min, 8%slope, ~4.4 km/h) improved insulin sensitivity by 32% (measured by hyperinsulinemic euglycemic clamp) in sheep.

Considering that spontaneous development of diabetes has been reported for sheep (among other domestic animals), perhaps these findings will benefit sheep as well. I doubt the farmers in the photo below knew they just might be improving insulin sensitivity when they put this animal to work:

 

Sources

McConell GK, Kaur G, Falcao-Tebas F, Hong YH, Gatford KL. Acute exercise increases insulin sensitivity in adult sheep: a new preclinical model.

Taniyama H, Shirakawa T, Furuoka H, Osame S, Kitamura N, Miyazawa K. Spontaneous Diabetes Mellitus in Young Cattle: Histologic, Immunohistochemical, and Electron Microscopic Studies of the Islets of Langerhans. Veterinary Pathology. 30: 46-54, 1993.

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This must have been quite a finding. I can image a sheep been put through its paces for reseach purposes. But as you mention it might be to their own benefit as well.

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it is true insulin play a big role in cotroling blood sugar level.when blood sugar level is high it stimulate the liver to convert glucose to glycogen u15198309

By rolindela pern… (not verified) on 16 Apr 2015 #permalink

Very interesting topic this is! I have also read about the research on insulin regarding the use of bacteria to grow the insulin needed for humans who suffer from the types of diabetes. What are your views on this research Dr Dolittle? This truly an interesting field i hope to go into oneday!

By M van Wyk (U15… (not verified) on 16 Apr 2015 #permalink

So animals should then obviously be allowed to run around in farms since it will benefit their lifespan right? Why do all farmers then not change to free range?
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By Schoombie JD (not verified) on 17 Apr 2015 #permalink

This is good news to the farmers that they can now be able to control their diabetic sheep. It also means that it will decrease mortality in sheep due to diabetes which will decrease starvation in our community. But does finding mean that farmers can control diabetes in other domesticated animals while being put to work?

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By Elwa Montshiwagagae (not verified) on 17 Apr 2015 #permalink

Very interesting approach using sheep as a model,makes sense to look into the physical attributes instead of using models thought to have brain chemistry closest to humans.

Exercising has always been the way, and now it has been proven even in animals. I at personal level can confidently say that a potential cure for diabetes has been discovered, just that it needs a little modification then its good to go!

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By Thamsanqa Mtshali (not verified) on 17 Apr 2015 #permalink

This is very interesting,I do however have a question: if i am correct the first synthetic insulin that was used to help diabetes originated from pigs,which then means that they should be the best test subjects for this test doesn't it?

By Herman Rossouw… (not verified) on 17 Apr 2015 #permalink

This is a great breakthrough for finding an alternative natural stimulant to curb insulin deficiencies.Increase in insulin sensitivity in these sheeps by means of exercises poses a greater chance of being applicable to humans. (14165865)

By T.G Tsotetsi (not verified) on 17 Apr 2015 #permalink

What are the results(insulin sensitivity) of the group of "control sheep" that had the same diet , were raised in the same area and by the same shepherds but did not take part in the exercise regime as the other sheep,this might help us compare between the groups and formulate conclusions.
Blogging assignment ,University of Pretoria u12075664

By Netshihanane M… (not verified) on 17 Apr 2015 #permalink

Interesting. I understand research should be done, but it is sad that animals are the only way to do it. I would just like to know how the sheep respond the treadmill experience?

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personally I think there is a positive and negative side to this theory. looking at it from a positive point of view sheep is a closer replica to the DNA of human beings therefore the outcome of the experiment will be more accurate than it would've been if the they used rodants. the cons in this case will include financing as the use of sheep will be more expensive it will also require a lot more space to house and keep the sheep save.

By Chalichia Wolmarans (not verified) on 18 Apr 2015 #permalink

It’s a shame that we have to use animal as test subjects to make discoveries and progress in medicine. But it´s a necessary evil, in order for us to have access to medicine that will help save someone close to us. u15140742

By Patricia Gonça… (not verified) on 18 Apr 2015 #permalink

i never knew that exercise improved insulin production. Very interesting. 15091784

New ways of study and trying to understand the possible effects certain things may have on curing or reducing the effects that diabetes has on people and animals is absolutely fascinating. This specific discovery, may lead to individuals who have been diagnosed with diabetes to increase their exercising habits - which in turn, lead them to live healthier lives. Thus these individuals may live longer, due to these healthy life styles.

By Jadene Jacobs … (not verified) on 18 Apr 2015 #permalink

It is quite interesting that muscle contraction is an alternative mechanism for lowering blood sugar. Plus the use of sheep as an alternative mammal in-order to improve the effectiveness of the experiment appears to be okay with the bioethics committee as it is not unethical and thus this is a great advancement in a treatment plan for diabetes. u15036945

By Jacqueline Maphutha (not verified) on 18 Apr 2015 #permalink

As far as my knowledge stretches pigs were used to create the first synthetic insulin to help diabetes.This must mean that they are closer relatives to us than sheep. Won't pigs be a better option then for this experiment as well?

By Herman Rossouw… (not verified) on 19 Apr 2015 #permalink

Yes Herman that is quite a good question,maybe the researchers found that sheep are better models as there were some problems in the past with people being allergic for pig insulin

Its interesting to find out that exercise can improve insulin production. u15091784

I think this is a good article. I really didn't know how important insulin is. It is also good that this insulin can be found in sheep , because farmers are now going to sell meat and Insulin. But I think this might have some side effects on people who are suffering from diabetes , who are allergic in sheeps. We also going to need more insulin , and as a result we might think of killing as much sheeps as possible. By killing sheeps , we are now decreasing the population of sheeps , of which is not good .

By Mhleli Emmanue… (not verified) on 19 Apr 2015 #permalink

So with increase of exercise the sensitivity to insulin improved in sheep? thus the decrease of glucose in the blood?

By Z.P. Booysen (… (not verified) on 19 Apr 2015 #permalink

THAT'S SO COOOL.

It seems like most diseases that affect humans also affect animals, both domestic and wild. is this true DOC. U15156827

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Does using sheep for this diabetes research affect them negatively in the long run?

By Majola silindokuhle (not verified) on 19 Apr 2015 #permalink

This is great news for diabetic people. does this mean that science is heading in the correct direction and may possibly eventually cure diabetes through testing sheep?

It's always nice to conduct innovative scientific researches in terms of finding new ways to improve life science statues. Creative Animodel is such a biotech company where you may find models for various studies. Here is the website: http://www.creative-animodel.com/. Thanks.