Is there something about the blood of a young organism that can improve the health of an older one? Three recent publications from Harvard and Stanford suggest there is such a factor. The notion of helping people who suffer the debilitating diseases common to old age has generated enormous public exposure.
It is unfortunate that in the rush to herald these findings, a significant detail was glossed over. These findings were derived from mice who were literally sewn together. In this procedure, called “parabiosis,” two mice are anesthetized, large skin incisions are made in each mouse, and then they are sutured together. Over time, blood vessels will grow across the surgical site, linking the circulations of the animals. As one can imagine, this is a tremendously stressful procedure, forcing two individual animals to act as one. In many cases, animals will try to tear apart from each other for days before finally giving up—an act of “learned helplessness” as it is known in the field of psychology.
How does a study, where mice are surgically conjoined, relate to a human condition? Was the pain and distress caused to the animals worth the potential results? These are difficult questions that must be continuously asked—before, during, and after the study, not just within the grant review or animal protocol approval process. Whether the answers support or refute the need for the study, they should be part of the scientific discussion.