Mad Science 2006 : Female rats die trying to pass urine
A team of scientists at the London Royal Free Hospital studied the effects of partial bladder obstruction in female rats, by anaesthetising eight animals, cutting open their abdomens and applying a jeweller’s silver ‘jump’ ring around their urinary passages.
Five other rats underwent the same surgical procedure, but without the application of the ring to their urinary passage. These five animals served as ‘controls’ (used for comparative purposes).
Two rats from the first group died three days after surgery, due to the effects of their over-full bladders. All of the remaining rats were killed after three weeks, by being administered carbon dioxide and then having their necks broken.
The researchers noted that the damage seen in the rat bladders was quite different from that seen in humans and in rabbits. They also stressed that such animal studies should be interpreted with caution since there are ‘marked species differences’ in the way human and animal bladders function. The cause of a weakened bladder in these rats was the result of an over-full bladder, due to a deliberate manipulation. However, as the researchers point out, the various underlying causes of urinary incontinence in humans is something that is still poorly understood.
Ref. Banks FCL, Knight GE, Calvert RC, Morgan RJ, Burnstock G. British Journal of Urology 2005; 97:372-378. ‘Alterations in purinergic and cholinergic components of contractile responses of isolated detrusor contraction in a rat model of partial bladder outlet obstruction.’