Age related changes in the functional, biochemical and molecular properties of alpha1-adrenoceptors in the rat genitourinary tract

J Urol. 2006 Sep;176(3):1214-9. doi: 10.1016/j.juro.2006.04.038.

Abstract

Purpose: Because age related changes occur in the properties of alpha(1)-adrenoceptor in several mammalian tissues and alpha(1)-adrenoceptor antagonists are extensively used to treat lower urinary tract symptoms secondary to benign prostatic hyperplasia, we investigated age related changes in the functional, biochemical and molecular properties of alpha(1)-adrenoceptor in the rat genitourinary tract.

Materials and methods: The characteristics of alpha(1)-adrenoceptor in the ventral and dorsolateral prostate, and bladder base and dome of 3 and 22-month-old rats were determined using an isolated muscle bath, radioligand receptor binding and real-time reverse transcriptase-polymerase chain reaction techniques.

Results: Old rats had significantly higher body weight, lower testosterone, a smaller ventral prostate and a larger bladder dome than young rats. Although there was no significant age dependent difference in the properties of alpha(1)-adrenoceptor in the bladder base and dome, total alpha(1)-adrenoceptor density, mRNA expression of all 3 alpha(1)-adrenoceptor subtypes (alpha(1A), alpha(1B) and alpha(1D)) and the maximum contractile responses to phenylephrine were significantly lower in the ventral and dorsolateral prostate of 22 vs 3-month-old rats.

Conclusions: Age related differences in the molecular, biochemical and functional properties of alpha(1)-adrenoceptors in the rat genitourinary tract may indicate potential differences in the response to alpha(1)-adrenoceptor antagonists with aging, ie a decrease in the therapeutic response in old vs young rats in the response to alpha(1)-adrenoceptor antagonists when used to treat lower urinary tract symptoms secondary to benign prostatic hyperplasia.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Age Factors
  • Animals
  • In Vitro Techniques
  • Male
  • Muscle Contraction
  • Muscle, Smooth / physiology
  • Prostate / physiology*
  • Rats
  • Rats, Inbred F344
  • Receptors, Adrenergic, alpha-1 / physiology*
  • Urinary Bladder / physiology*

Substances

  • Receptors, Adrenergic, alpha-1