内皮素-1在兔阴茎海绵体中的药理特性。

Pharmacological properties of endothelin-1 in the rabbit corpus cavernosum.

作者信息

Mumtaz Faiz H, Lau David H W, Siddiqui Emad J, Thompson Cecil S, Morgan Robert J, Mikhailidis Dimitri P

机构信息

Department of Urology, Royal Free Hospital and University College Medical School, University College London, Rowland Hill Street, London NW3 2PF, UK.

出版信息

In Vivo. 2006 Mar-Apr;20(2):243-6.

PMID:16634525

Abstract

BACKGROUND

Endothelin (ET-1) may play a role in the regulation of erection but this has not been conclusively demonstrated. Augmented cavernosal smooth muscle (CSM) contraction in the rat occurs following exposure to both ET-1 and phenylephrine (PE; alpha-1 agonist). The aim of this study was to assess the effect of ET-1 and its possible role in the alpha1-adrenergic pathway during the erectile process.

MATERIALS AND METHODS

Organ bath studies were performed on CSM strips of penises obtained from 12 age-matched New Zealand White rabbits. The effect of ET-1 and PE alone on CSM tone in the absence and presence of ETA (BQ123) and ETB (BQ788) antagonists was assessed. Tissue responses were measured as tension (newton, N). EC50 values are expressed as mean +/- S.E.M.

RESULTS

PE (10(8) - 10(-4) M) and ET-1 (10(-10) - 10(-6) M) produced a concentration-dependent contraction in rabbit CSM strips. The EC50 values were 1.7 x 10(-7) M +/- 1.1 and 3.4 x 10(-9) M +/- 1.5, respectively. BQ123 10(-5) M significantly inhibited ET-1-mediated CSM contractions more than BQ788 10(-5) M (both ANOVA p<0.01). The EC50 were 1.3 x 10(-6) M +/- 2.6 and 2.0 x 10(-7) M +/- 2.1, respectively. Neither the ETA or ETB receptor antagonist had a significant influence on alpha1-adrenergic receptor-mediated CSM contraction.

CONCLUSION

ETA receptors may play a greater role than ETB receptors in ET-1-induced rabbit CSM contraction and the detumescence process. The a1-adrenergic-dependent pathway does not involve the ETA or ETB receptors.

摘要

背景

内皮素（ET-1）可能在勃起调节中发挥作用，但这尚未得到确凿证实。大鼠海绵体平滑肌（CSM）在暴露于ET-1和去氧肾上腺素（PE；α-1激动剂）后会出现收缩增强。本研究的目的是评估ET-1在勃起过程中的作用及其在α1-肾上腺素能途径中的可能作用。

材料与方法

对12只年龄匹配的新西兰白兔阴茎的CSM条进行器官浴研究。评估了单独的ET-1和PE在存在和不存在ETA（BQ123）和ETB（BQ788）拮抗剂的情况下对CSM张力的影响。组织反应以张力（牛顿，N）来衡量。EC50值以平均值±标准误表示。

结果

PE（10⁻⁸ - 10⁻⁴ M）和ET-1（10⁻¹⁰ - 10⁻⁶ M）在兔CSM条中产生浓度依赖性收缩。EC50值分别为1.7×10⁻⁷ M±1.1和3.4×10⁻⁹ M±1.5。10⁻⁵ M的BQ123比10⁻⁵ M的BQ788更能显著抑制ET-1介导的CSM收缩（两者方差分析p<0.01）。EC50分别为1.3×10⁻⁶ M±2.6和2.0×10⁻⁷ M±2.1。ETA或ETB受体拮抗剂对α1-肾上腺素能受体介导的CSM收缩均无显著影响。