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Updated: Jan 22, 2026
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Detrusor Underactivity Model in Rats by Conus Medullaris Transection
Published on: August 28, 2020
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Differences between young and aged rats in voiding frequency and detrusor muscle serotonergic contraction
Asaki Takanashi1, Azuki Sakai-Saito2, Tsuyoshi Hattori3
1Faculty of Health Care and Nursing, Juntendo University, Chiba, Japan; Division of Medical Education, Juntendo University School of Medicine, Tokyo, Japan.
Experimental Gerontology
|July 1, 2019
Summary
Aging alters rat urination patterns, with reduced frequency and longer intervals. Serotonin
Area of Science:
- Urology
- Gerontology
- Pharmacology
Background:
- Aging is associated with changes in lower urinary tract symptoms.
- The role of serotonin (5-HT) in age-related urinary dysfunction is not fully understood.
Purpose of the Study:
- To compare voiding function in young versus aged rats.
- To investigate serotonin-induced detrusor muscle contractions in young and aged rats.
Main Methods:
- Voiding function parameters (frequency, volume, interval) were analyzed in young and aged Fischer 344 rats.
- Bladder strips were used to measure serotonin-induced contractions, with and without antagonists like ketanserin and naftopidil.
- Electrical field stimulation (EFS) was employed to assess neurogenic contractions.
Main Results:
- Aged rats showed decreased voiding frequency and prolonged voiding intervals.
- Serotonin's potency (pEC50) in inducing detrusor contraction was reduced in aged rats, though maximal response remained unchanged.
- Ketanserin partially inhibited serotonin-induced contractions, while naftopidil's effect was limited, particularly in aged bladders.
Conclusions:
- Aging significantly alters rat urination rhythm and detrusor muscle response to serotonin.
- The reduced efficacy of serotonin and naftopidil in aged bladders suggests age-related changes in 5-HT receptor function or signaling pathways.
- Serotonin does not appear to mediate the atropine-resistant EFS-induced contractions in aged rat bladders.
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