Ichiro Hirotsu (#), Chieko Hayano and Tadato Tani
High Quality-Life Research Laboratories, Sumitomo Metal Industries, Ltd.,
3-5, Hikaridai, Seika-cho, Soraku-gun, Kyoto 619-02, Japan
(#) Present address for correspondence: Department of Pharmacology and Toxicology,
Rohto Pharmaceutical Co., Ltd., 1-8-1, Tatsumi-Nishi, Ikuno-ku, Osaka 544,
Japan
Abstract: The effect of bethanechol, a muscarinic agonist, was
studied by cystometrography in conscious rats with bilateral pelvic nerve
(PN) lesions. In sham-operated rats, the transvesical infusion of saline
elicited regularly micturition. The micturition was abolished by the bilateral
PN transection, resulting in overflow incontinence. Bethanechol (30 mg/kg),
administered orally to denervated rats, significantly increased the micturition
frequency. Therefore, the micturition seems to be largely dependent upon
muscarinic receptors of the bladder, and the finding supports the clinical
effect of bethanechol. Moreover, this animal model may be useful for studying
the overflow incontinence from detrusor failure of neuropathic origin.
Keywords: Bethanechol, Overflow incontinence, Pelvic nerve (rat)