title: Evidence for the presence of alpha1 adrenoceptor subtypes in the human ureter.
abstract: OBJECTIVE
  Several studies have proposed a role for alpha1 adrenoceptors (ARs) in ureteral physiology, indicating that they are present in the ureter; however, few studies have been done to identify alpha1 AR subtypes present in this area. Thus, this study was carried out to characterize the alpha1 AR subtype gene and protein expression in proximal, medial, and distal region of the human ureter.
  
  
  METHODS
  Molecular characterization of alpha1 AR subtypes were analyzed by semi-quantitative RT-PCR. alpha1 AR protein expression was studied by saturation binding curves and by competition binding curves with selective antagonists. Analysis of data was performed using the GraphPad PRISM 4 software.
  
  
  RESULTS
  Analysis of saturation binding curves revealed a heterogeneous distribution of alpha1 AR binding sites, the B(max) for the distal ureter was indeed 52.5 +/- 5.4 fmol/mg prot, while a lower similar density of alpha1 ARs was demonstrated in the medial (25.2 +/- 1.7 fmol/mg prot) and proximal (23.4 +/- 0.4 fmol/mg prot) ureters. Molecular and pharmacological characterization of alpha1 AR subtypes indicated that each receptor was present, although with differences in terms of the amount expressed.
  
  
  CONCLUSIONS
  Human ureter was endowed with each alpha1 AR subtype, although alpha1D and alpha1A ARs were prevalent over alpha1B ARs. Radioligand binding results revealed that there were no significant differences in the K(d) between ureteral regions, while a heterogeneous distribution of alpha1 AR binding sites was detected, with the highest density of alpha1 ARs in the distal ureter and a lower similar density in the medial and proximal ureters.
authors.affiliation: Section of Pharmacology, Department of Biomedical Science and Biotechnology, University of Brescia Medical School, Brescia, Italy. sigala@med.unibs.it
authors.forename: Sandra
authors.initials: S
authors.lastname: Sigala
authors.forename: Marco
authors.initials: M
authors.lastname: Dellabella
authors.forename: Giulio
authors.initials: G
authors.lastname: Milanese
authors.forename: Sara
authors.initials: S
authors.lastname: Fornari
authors.forename: Stefania
authors.initials: S
authors.lastname: Faccoli
authors.forename: Francesca
authors.initials: F
authors.lastname: Palazzolo
authors.forename: Angelo
authors.initials: A
authors.lastname: Peroni
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Mirabella
authors.forename: Sergio Cosciani
authors.initials: SC
authors.lastname: Cunico
authors.forename: PierFranco
authors.initials: P
authors.lastname: Spano
authors.forename: Giovanni
authors.initials: G
authors.lastname: Muzzonigro
mesh_terms: D000368:Aged; D005260:Female; D015870:Gene Expression; D006801:Humans; D007457:Iodine Radioisotopes; D008297:Male; D008875:Middle Aged; D011869:Radioligand Assay; D018340:Receptors, Adrenergic, alpha-1 / Q000235:genetics* / Q000378:metabolism*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014513:Ureter / Q000502:physiology*
chemical_list: D007457:Iodine Radioisotopes; D018340:Receptors, Adrenergic, alpha-1