Abstract
The aim of this work is to report a detailed study of the presence of α1 AR subtypes in human urinary bladder areas involved in the micturition (i.e. detrusor, trigone and neck), investigating whether or not there are differences between sexes.
Methods
Urinary bladder specimens were obtained as discarded tissue after cystectomy for vesical carcinoma (17 men and 14 women). Molecular characterization of α1 AR subtypes was done by semi-quantitative RT-PCR. The α1 AR protein expression was studied by saturation binding curves using the α1 AR antagonist 125I-HEAT and by western blot. Analysis of data was performed using the GraphPad PRISM 4 software.
Results
Results obtained indicated that α1 AR proteins were detectable in each bladder area. In both sexes, the detrusor and the neck expressed similar levels of α1 ARs: respectively, detrusor: 14.6 ± 1.2 in men and 13.1 ± 1.1 fmol/mg prot in women; neck: 16.9±3.2 in men and 17.5 ± 4.1 fmol/mg prot in women. In the trigone, significantly higher α1 ARs were found in women compared to men (20.6 ± 1.1 vs 11.7 ± 0.7 fmol/mg prot). Subtype analysis indicated that in women, each area was endowed with mRNA and protein encoding for each α1 AR subtype. The men detrusor expressed α1A and α1D ARs, while in the trigone and the neck, each subtype was present.
Conclusions
A selective distribution of α1 ARs did exist between sexes and between the different areas involved in micturition, supporting evidence which indicates a role of different α1 AR subtypes in the pathophysiology of the lower urinary tract symptoms.
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