Apelin hormone injections powerfully lower blood sugar

Nov 04, 2008

By injecting a hormone produced by fat and other tissues into mice, researchers report in the November Cell Metabolism that they significantly lowered blood sugar levels in normal and obese mice. The findings suggest that the hormone known as apelin might be a promising target for managing insulin resistance and type 2 diabetes.

Insulin resistance, in which normal amounts of insulin are insufficient to lower blood sugar (glucose) levels, is a precursor to diabetes.

" The effects of apelin appear to be similar to insulin," although they operate in different ways, said Isabelle Castan-Laurell of Institut National de la Santé et de la Recherche Médicale and Université de Toulouse.

Earlier studies had suggested a link between apelin and insulin, Castan-Laurell said. Apelin levels were shown to parallel insulin levels in mice and humans. Apelin levels in the blood also rise in those who are obese and in those with type 2 diabetes.

Those findings led the researchers to suspect that apelin and insulin might have other similarities.

Now, they show that acute intravenous injections of apelin have a powerful blood sugar-lowering effect on mice. They also show evidence that apelin stimulates muscle and fat tissue to take up glucose from the bloodstream by stimulating a known glucose transport pathway. Specifically, apelin activates a pathway including an enzyme called AMP-activated protein kinase (AMPK), which plays a pivotal role in the control of skeletal muscle glucose and the metabolism of fatty acids.

Moreover, they showed that apelin treatment restores glucose tolerance and improves glucose uptake in mice that are obese and insulin resistant.

Castan-Laurell said they aren't quite sure yet what it means that obese individuals tend to have high apelin levels. It could be that apelin levels don't rise enough to curb rising blood sugar or perhaps insulin resistance without apelin would be even worse. Alternatively, obese animals and humans might grow resistant to the action of apelin just as they do insulin.

The researchers said they will now examine the effects of chronic apelin treatment in the mice to see if the hormone can ward of obesity and insulin resistance in the longer term.

" In conclusion," the researchers wrote, "the present study reveals apelin as a new endocrine regulator of AMPK and strengthens the crosstalk between [fat] and skeletal muscle. The involvement of AMPK in apelin-mediated glucose uptake represents an attractive pathway that could conceivably lead to a new drug target for the treatment of metabolic disorders."

Either way, they added, the discovery offers new insights into the physiology of glucose and lipid metabolism in health and disease.

Source: Cell Press

Explore further: Efforts to save rare northern white rhino continue

add to favorites email to friend print save as pdf

Related Stories

People finding their 'waze' to once-hidden streets

1 hour ago

When the people whose houses hug the narrow warren of streets paralleling the busiest urban freeway in America began to see bumper-to-bumper traffic crawling by their homes a year or so ago, they were baffled.

Identity theft victims face months of hassle

2 hours ago

As soon as Mark Kim found out his personal information was compromised in a data breach at Target last year, the 36-year-old tech worker signed up for the retailer's free credit monitoring offer so he would ...

Observers slam 'lackluster' Lima climate deal

2 hours ago

A carbon-curbing deal struck in Lima on Sunday was a watered-down compromise where national intransigence threatened the goal of a pact to save Earth's climate system, green groups said.

Your info has been hacked. Now what do you do?

2 hours ago

Criminals stole personal information from tens of millions of Americans in data breaches this past year. Of those affected, one in three may become victims of identity theft, according to research firm Javelin. ...

New Bond script stolen in Sony hack

2 hours ago

An "early version" of the screenplay for the new James Bond film was the latest victim of a massive hacking attack on Sony Pictures Entertainment, its producers said in a statement on their website Sunday.

Ag-tech could change how the world eats

7 hours ago

Investors and entrepreneurs behind some of the world's newest industries have started to put their money and tech talents into farming - the world's oldest industry - with an audacious agenda: to make sure there is enough ...

Recommended for you

A vegetarian carnivorous plant

3 hours ago

Carnivorous plants catch and digest tiny animals in order and derive benefits for their nutrition. Interestingly the trend towards vegetarianism seems to overcome carnivorous plants as well. The aquatic carnivorous bladderwort, ...

The origin of the language of life

4 hours ago

The genetic code is the universal language of life. It describes how information is encoded in the genetic material and is the same for all organisms from simple bacteria to animals to humans. However, the ...

User comments : 0

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.