Bond Urology Group, Bond University Faculty of Health Sciences and Medicine, Gold Coast, Queensland, Australia.
Urology. 2013 Jan;81(1):211.e1-7. doi: 10.1016/j.urology.2012.09.011. Epub 2012 Nov 30.
To investigate the role of adrenoceptor subtypes in regulating the spontaneous contractile activity of the inner lining of the urinary bladder (urothelium/lamina propria).
The responses of isolated strips of porcine urothelium/lamina propria to noradrenaline, phenylephrine, and isoprenaline were obtained in the absence and presence of receptor subtype-selective antagonists. Quantitative reverse-transcriptase polymerase chain reaction was undertaken to assess the expression of adrenoceptor genes.
The tissues expressed all α1- and β-adrenoceptor subtypes, with the α1A-, α1B-, and β2-adrenoceptors the predominant receptors at the messenger RNA level. In the functional experiments, the rate of phasic contractions and the basal tension were increased by the α1-adrenoceptor agonists phenylephrine (100 μM) and A61603 (10 μM). The rate and tension responses to phenylephrine were reduced by low concentrations of tamsulosin (3 nM) and RS100329 (10 nM) but were unaffected by BMY7378 (100 nM), prazosin (10 nM), and RS17053 (1 μM). In contrast, isoprenaline and salbutamol (both 1 μM) induced a relaxation of tissues and slowing of phasic contractions. The rate and tension responses to isoprenaline were inhibited by propranolol (100 nM) or a combination of CGP20712A (30 nM) and ICI118551 (70 nM). The rate responses were also significantly inhibited by ICI118551 alone (70 nM).
Although all α1- and β-adrenoceptor subtypes were expressed in the pig urothelium/lamina propria, the α1A/L-adrenoceptor appeared to mediate increases in the contractile rate and tension. The β-adrenoceptor induced inhibition of spontaneous contractile activity appears to be predominately mediated by β2-adrenoceptors, with β1- and β2-adrenoceptors possibly involved in the tension responses.
研究肾上腺素能受体亚型在调节膀胱内层（尿路上皮/固有层）自发性收缩活动中的作用。
在不存在和存在受体亚型选择性拮抗剂的情况下，获得猪尿路上皮/固有层分离条带对去甲肾上腺素、苯肾上腺素和异丙肾上腺素的反应。进行定量逆转录聚合酶链反应以评估肾上腺素能受体基因的表达。
组织表达所有 α1-和 β-肾上腺素能受体亚型，α1A-、α1B-和 β2-肾上腺素能受体在信使 RNA 水平上是主要受体。在功能实验中，α1-肾上腺素能受体激动剂苯肾上腺素（100 μM）和 A61603（10 μM）增加了相位收缩的频率和基础张力。苯肾上腺素的速率和张力反应被低浓度的坦索罗辛（3 nM）和 RS100329（10 nM）减少，但不受 BMY7378（100 nM）、哌唑嗪（10 nM）和 RS17053（1 μM）的影响。相比之下，异丙肾上腺素和沙丁胺醇（均为 1 μM）诱导组织松弛和相位收缩减慢。异丙肾上腺素的速率和张力反应被普萘洛尔（100 nM）或 CGP20712A（30 nM）和 ICI118551（70 nM）的组合抑制。速率反应也被 ICI118551 单独（70 nM）显著抑制。
尽管猪尿路上皮/固有层中均表达所有 α1-和 β-肾上腺素能受体亚型，但 α1A/L-肾上腺素能受体似乎介导收缩率和张力的增加。β-肾上腺素能受体诱导的自发性收缩活动抑制似乎主要由 β2-肾上腺素能受体介导，β1-和 β2-肾上腺素能受体可能参与张力反应。
