Our rats are getting fat

Via everyone's favorite drug discovery blog, In the Pipeline, the news that the rats and mice we depend on to understand the effectiveness of drugs and other metabolically significant interventions are pathetic, out-of-shape, metabolically deranged lardballs.

The authors of the study paper describe your typical laboratory rodent as "sedentary, obese, glucose intolerant, and on a trajectory to premature death". This matters because almost every metabolic pathway is affected by this situation: "cellular physiology, vulnerability to oxidative stress, inflammation, and associated diseases".

Of course, as everyone instantly points out, this makes these rodents excellent subjects for testing drugs and procedures intended for our increasingly sedentary and obese population. But no one should be happy about that. At the very least, we should know when a drug has been tested on (or controlled against) a rodent with a stressed metabolism, because its effect in normal-weight humans might be quite different. And there are still some of us around.

This leads to several related thoughts:

• "Sedentary and obese" is a different state than "active and normal weight". The differences are many, sometimes unexpected, and often profound.
• Being sedentary and obese has many unpleasant side effects:  note the "trajectory to premature death" part. The differences between "sedentary and obese" and "active and normal weight" are negative, not neutral.
• It's easy to become sedentary and obese. It doesn't require television or ads by snack companies.
• As a result, changing from "sedentary and obese" to "active and normal weight" will no doubt entail a huge amount of work and cost from the managers of these animals.

What distinguishes us from lab rats is (presumably) our conscious ability to alter our circumstances.  Don't be a lab rat.