title: Long-term caloric restriction in rats may prevent age related impairment of in vitro bladder function.
abstract: OBJECTIVE
  Bladder function is often impaired with aging. In other organs caloric restriction has had a prophylactic effect on the biological changes associated with aging. We tested the hypothesis that long-term caloric restriction can prevent age related impaired bladder function in the rat.
  
  
  METHODS
  Fisher 344 male rats were divided into 3 groups, including 16 young rats at age 6 months with free access to normal food, 15 old rats at age 25 to 28 months with free access to normal food and 16 old rats at age 25 to 28 months fed with normal food 3 days per week since age 6 weeks (caloric restriction). We performed frequency volume measurements, in vitro organ bath functional studies using full-thickness longitudinal detrusor strips, evaluation of muscarinic and purinergic receptor mRNA expression, and histological examination with Masson trichrome staining of bladder tissue.
  
  
  RESULTS
  Frequency volume changes did not significantly differ among the 3 groups. The old group fed normal food showed weaker contractile responses to carbachol and electrical field stimulation (especially in the cholinergic component), lower M3 receptor mRNA expression and higher collagen deposition compared to the young group. These age related bladder changes were milder in the old group with caloric restriction than in the old group fed normal food.
  
  
  CONCLUSIONS
  This study suggests that in the rat long-term caloric restriction has a preventive effect against age related functional and morphological bladder changes. These changes include impaired detrusor contractility that may be related to decreased expression of M3 receptors and to bladder wall fibrosis.
authors.affiliation: Department of Continence Medicine, University of Tokyo Graduate School of Medicine, Tokyo, Japan; Department of Urology, Yokohama City University Graduate School of Medicine, Yokohama, Japan.
authors.forename: Hiroki
authors.initials: H
authors.lastname: Ito
authors.affiliation: Department of Continence Medicine, University of Tokyo Graduate School of Medicine, Tokyo, Japan.
authors.forename: Naoki
authors.initials: N
authors.lastname: Aizawa
authors.affiliation: Research Team for Mechanism of Aging, Tokyo Metropolitan Institute of Gerontology, Tokyo, Japan.
authors.forename: Yasunori
authors.initials: Y
authors.lastname: Fujita
authors.affiliation: Department of Urology, University of Tokyo Graduate School of Medicine, Tokyo, Japan.
authors.forename: Motofumi
authors.initials: M
authors.lastname: Suzuki
authors.affiliation: Department of Urology, University of Tokyo Graduate School of Medicine, Tokyo, Japan.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Fukuhara
authors.affiliation: Department of Urology, University of Tokyo Graduate School of Medicine, Tokyo, Japan.
authors.forename: Yukio
authors.initials: Y
authors.lastname: Homma
authors.affiliation: Department of Urology, Yokohama City University Graduate School of Medicine, Yokohama, Japan.
authors.forename: Yoshinobu
authors.initials: Y
authors.lastname: Kubota
authors.affiliation: Research Team for Mechanism of Aging, Tokyo Metropolitan Institute of Gerontology, Tokyo, Japan.
authors.forename: Masafumi
authors.initials: M
authors.lastname: Ito
authors.affiliation: Aarhus Institute of Advanced Studies, Aarhus University, Aarhus, Denmark.
authors.forename: Karl-Erik
authors.initials: KE
authors.lastname: Andersson
authors.affiliation: Department of Continence Medicine, University of Tokyo Graduate School of Medicine, Tokyo, Japan. Electronic address: yigawa-jua@umin.ac.jp.
authors.forename: Yasuhiko
authors.initials: Y
authors.lastname: Igawa
mesh_terms: D000367:Age Factors; D000818:Animals; D031204:Caloric Restriction; D066298:In Vitro Techniques; D008297:Male; D051381:Rats; D011916:Rats, Inbred F344; D013997:Time Factors; D001743:Urinary Bladder / Q000503:physiopathology*; D001745:Urinary Bladder Diseases / Q000517:prevention & control*
keywords: aging; caloric restriction; collagen; muscle contraction; urinary bladder