Rats, Blue M&M's, and Ethics

A bit ago, Slashdot had an article titled Dye Used In Blue M&Ms Can Lessen Spinal Injury. Here is a quote from the Slashdot synopsis of the original article:

Researchers at the University of Rochester Medical Center have found that the dye used in blue M&Ms and other foods can, when given intravenously to a lab rat shortly after a spinal injury, minimize secondary damage caused by the body when it kills off nearby healthy cells.

As usual, the article is somewhat interesting, but the comments that followed are where the real fun is.

Query in one comment:

Are rats less deserving of our sympathies than "intelligent" humans?

Someone's reply:

Are these humans lawyers, music industry executives, or Microsoft programmers? Context is key.

I understand that saving human lives is really important, but I am wary of getting cavalier about what we do to other animals in the name of progress. I'm not sure how this relates to my stance on eating meat, but disliking sport hunting and maim and release fishing. Killing animals to eat them is a totally different thing from hurting them for sport, but scientific research seems to be in a more ambiguous place. The potential for benefit to humans is great, but the cruelty seems great as well.

I'm not about to join PETA, but I hope the people who perform and benefit from this sort of research think about the terrible things these animals have been subjected to for our benefit.