Drug used to treat glaucoma might prove effective in managing obesity

A new study has found that a drug primarily used to treat the eye condition glaucoma might also prove effective in managing obesity. Scientists at Yale University have found a way to restrict fat absorption into the body by altering the shape of cells in the gut that usually allow this to happen.

The research is the first study to show that lymphatic vessel portals in the gut, called lacteals, are fundamental in the uptake of fat into the body.  Two key genes in gut cells were identified which, when removed, caused the gut cells to become ‘zippered’ rather than staying open in a button shape.

The research is the first study to show that lymphatic vessel portals in the gut, called lacteals, are fundamental in the uptake of fat into the body

It was found that fat particles can no longer pass through zippered lacteals, causing excretion of fat rather than absorption. The study compared altered mice with the genes missing to normal mice. Over a period of 8 weeks all mice were fed a high-fat diet, but while the normal mice quickly became obese, the unaltered mice remained the same weight.

Closing lacteals genetically isn’t an option, so having gained an understanding of this mechanism, the Yale group started to look for a group of drugs that might produce a similar effect in humans. The solution? A group of molecules known as Rock (Rho-kinase) inhibitors, already approved for use in treating glaucoma – a degenerative condition causing pressure on the optic nerve, resulting in blindness.

Over a period of 8 weeks all mice were fed a high-fat diet, but while the normal mice quickly became obese, the unaltered mice remained the same weight

When injected into mice, the inhibitor was shown to relax the internal support tension in gut cells, resulting in the ‘zipper’ effect in lacteals that inhibits fat absorption. The team, therefore, suggested that more research looking at the effects Rock inhibitors on lipid absorption and weight loss is now needed as these results could suggest that these drugs may be useful in treating obesity and regulating body weight.

Don’t give up the gym membership just yet though; while these results seem promising, independent experts warn of inadvertent side effects caused by shutting off this intestinal pathway. Zippering the junctions in lacteals could prevent the uptake of nutrients in fats, or compromise fluid drainage and immune cell trafficking.

Don’t give up the gym membership just yet though; while these results seem promising, independent experts warn of inadvertent side effects caused by shutting off this intestinal pathway

Whether or not glaucoma medication will be a viable option for controlling obesity in the future remains to be seen. Regardless, by discovering that the structure of junctions in lymphatic endothelial cells determines the absorption of intestinal fat, new avenues for research in the regulation of body weight are now open.