When it's two in the morning, there's nothing in the world more frustrating than being awakened by the urge to pee. Now, for the first time ever, researchers have shown that urination patterns are regulated by circadian rhythms (the molecular clock that controls your sleep/wake cycle, among other things.) Plus a specific protein that controls how much urine your bladder can hold.
The protein in question is called connexin43 (Cx43). Previous studies have shown that the bladders of mice with elevated Cx43 levels can hold less urine before signaling the urge to pee, and that normal mice — like humans — tend to urinate more frequently when they're awake.
In a study published in today's issue of Nature Communications, Japanese reachers led by Hiromitsu Negoro conducted a series of experiments linking Cx43 levels to circadian rhythms in mice. They found that levels of Cx43 in bladder muscle cells oscillate throughout the day in response to a well-documented circadian molecule called Rev-erbα. They also showed that mice with an abnormal Cx43 gene urinated less frequently than normal mice. Finally, the researchers demonstrated that mice genetically engineered to have dysfunctional circadian rhythms produced just as much urine as normal mice, but peed independently of regular night/day cycles.
What's cool about this study is that it provides researchers with two new ways of approaching problems like bedwetting in children and sleep-interrupting pee-urges in adults. The first is to adjust a person's circadian rhythms (this can be done by changing their sleep patterns, or prescribing medication.) The second is to identify specific therapeutic targets within the body — like the genes that express Cx43 in bladder muscles. [Nature Communications via Science]