What's in an Overactive Bladder?

Big potassium channel activity associated with bladder overactivity from prostate enlargement

/ Author:  / Reviewed by: Joseph V. Madia, MD

(RxWiki News) As a man grows older, it is not uncommon for his prostate to grow. An enlarged prostate can cause urinary problems, including overactive bladder. Recent research findings show how an enlarged prostate leads to overactive bladder.

Researchers found that bladder muscle contractions resulting from an enlarged prostate increased as big potassium channel activity decreased.

Big potassium channels - proteins involved in controlling muscle contractions - are associated with overactive bladder, according to a study funded by the National Institute of Diabetes and Digestive and Kidney Diseases.

"An enlarged prostate can lead to overactive bladder."

While this finding does not represent a giant leap forward in the treatment of overactive bladder, it does give us a better understanding of the urinary problems caused by an enlarged prostate. Other researchers can now build off of this study to find better ways to prevent and treat overactive bladder.

When the prostate gland enlarges, it presses against the urethra (the tube that takes urine from the bladder out of the body), blocking urine flow. In response, the bladder muscle becomes thicker so that it can squeeze out urine more forcefully.

The bladder muscle can also cause the bladder to contract even when it contains only a small amount of urine. The bladder muscle's overactivity can cause a man to urinate frequently and to feel like he has to urinate immediately.

Samuel Chacko, D.V.M., Ph.D., director of basic urological research at the University of Pennsylvania School of Medicine, and colleagues wanted to see if the bladder muscle's overactivity was related to changes in big potassium activity.

To study this potential relationship, researchers gave rabbits overactive bladder by blocking the animals' urethras. Then, they measured contractions and big potassium activity of the bladder muscle.

They found that decreases in big potassium channel activity were associated with increases in bladder muscle contractions.

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Review Date: 
April 4, 2011
Last Updated:
April 8, 2011