Erschienen in:
01.12.2009 | Original Article
Gene expressions and mechanical functions of α1-adrenoceptor subtypes in mouse ureter
verfasst von:
Shinya Kobayashi, Yoshitaka Tomiyama, Yuji Hoyano, Yoshinobu Yamazaki, Hiroshi Kusama, Yasunori Itoh, Yasue Kubota, Kenjiro Kohri
Erschienen in:
World Journal of Urology
|
Ausgabe 6/2009
Einloggen, um Zugang zu erhalten
Abstract
Purpose
This study was performed to characterize the α1-adrenoceptor subtypes in mouse ureters as regards gene expressions and contractile functions.
Methods
The mRNAs for these subtypes were quantified by the real-time quantitative reverse transcription polymerase chain reaction. In a functional study, α1-adrenoceptor antagonists were evaluated against the noradrenaline-induced contraction in mouse isolated ureteral preparations.
Results
In mouse ureter, the relative mRNA expression levels for α1a-, α1b- and α1d-adrenoceptors were 74.5, 14.3 and 11.2%, respectively. Adrenaline and noradrenaline each produced a concentration-dependent phasic contraction (pD
2 values, 5.73 ± 0.05 and 5.69 ± 0.06, respectively). Prazosin (non-selective α1-adrenoceptor antagonist), silodosin (selective α1A-adrenoceptor antagonist), and BMY-7378 (selective α1D-adrenoceptor antagonist) all shifted the concentration–response curve for noradrenaline to the right, the rank order of potencies (apparent pA
2 values) being silodosin (9.32 ± 0.11) > prazosin (8.55 ± 0.10) > BMY-7378 (6.06 ± 0.15). The α1A-adrenoceptor antagonist silodosin was thus much more effective than the α1D-adrenoceptor antagonist BYM-7378.
Conclusions
Our results demonstrate that in mouse ureters: the mRNA for the α1A-adrenoceptor was more prevalent than those for the α1B- and α1D-adrenoceptors, and that among these subtypes, the α1A-adrenoceptor plays the major role in noradrenaline-induced contraction.