Dietary phytoestrogens maintain contractile responses to carbachol with age in the female rat isolated bladder

Life Sci. 2011 Aug 15;89(7-8):213-20. doi: 10.1016/j.lfs.2011.05.022. Epub 2011 Jun 13.

Abstract

Aims: Development of urinary incontinence, for many women, occurs following menopause. Dietary phytoestrogens consumed over the long term may affect the contractile function and maintenance of the urinary bladder in post menopausal women. This study examined the muscarinic receptor mediated contractile responses in the rat isolated bladder in response to ovariectomy and long term dietary phytoestrogen consumption.

Main methods: Ovariectomised or sham-operated female Wistar rats (8 weeks) were fed either normal rat chow (soy, phytoestrogens) or a non-soy (phytoestrogen free) diet. Bladders were dissected from rats at 12, 24 and 52 weeks of age and placed in 25 ml organ baths filled with McEwans solution.

Key findings: The contractile response to carbachol, in 12 week old female rats did not change as a result of dietary phytoestrogens or ovariectomy (P>0.05). At 24 weeks of age, detrusor muscle strip responses to carbachol from non-soy fed ovariectomised rats were attenuated (P<0.05). At 52 weeks, bladder detrusor strip responses to carbachol were reduced in all treatment groups with the exception of the soy-fed sham operated rats.

Significance: These results suggest an age-related reduction in the contractile response of the detrusor to the muscarinic receptor agonist carbachol, which may be prevented by long term dietary phytoestrogen intake.

MeSH terms

  • Age Factors
  • Animal Feed
  • Animals
  • Body Weight / drug effects
  • Carbachol / pharmacology*
  • Cholinergic Agonists / pharmacology*
  • Female
  • Glycine max
  • In Vitro Techniques
  • Muscle Contraction / drug effects*
  • Muscle, Smooth / drug effects
  • Muscle, Smooth / pathology
  • Muscle, Smooth / physiopathology
  • Organ Size / drug effects
  • Ovariectomy
  • Phytoestrogens / administration & dosage*
  • Rats
  • Rats, Wistar
  • Receptors, Muscarinic
  • Soybean Proteins / administration & dosage*
  • Urinary Bladder / drug effects*
  • Urinary Bladder / pathology
  • Urinary Bladder / physiopathology
  • Urinary Bladder, Overactive / diet therapy
  • Urinary Bladder, Overactive / prevention & control

Substances

  • Cholinergic Agonists
  • Phytoestrogens
  • Receptors, Muscarinic
  • Soybean Proteins
  • Carbachol