Xiao Yan-yan, Han Ling
Department of Pediatric Cardiology, Anzhen Hospital Affiliated to Capital University of Medical Sciences, Beijing, 100029, China.
Zhonghua Er Ke Za Zhi. 2004 Jul;42(7):502-6.
During the development of hypoxic pulmonary hypertension, the quantity of the protein and mRNA of alpha1-adrenergic receptor (alpha1-adrenergic receptor,alpha1-AR) in the lung tissue increased, while no particular reports were found about the change of the alpha1-AR subtypes during that course. The study aimed to understand the quantity and location of alpha1-AR subtypes mRNA expression in control and hypoxia rats,and the effect of phentolamine in hypoxic pulmonary hypertension.
Fifty-five male Wistar rats were divided randomly into 5 groups: control group (n = 10), hypoxia 2 weeks (n = 13), hypoxia 4 weeks (n = 10), saline control group (n = 10) and hypoxia 4 weeks plus phentolamine group (n = 12). Semi-quantitative reverse transcription and polymerase chain reaction (RT-PCR) were used to examine the mRNA expression of alpha1-AR subtypes in each group. In situ hybridization was also used to detect the location of the alpha1-AR in lungs of normal rats.
(1) The pulmonary artery pressure increased with the extension of hypoxia. (2) The results of RT-PCR showed that the mRNA expression of alpha1A-AR was the most,alpha1B-AR the second and alphaZD-AR was the least in all of the groups. (3) The expression of alpha1A-AR and alpha1B-AR mRNA increased with the extension of hypoxia, and the expressions among groups showed difference. (4) The expression of alpha1D-AR also increased with the extension of hypoxia but no difference was found among groups. (5) No difference was found in mRNA quantity of all three subtypes between phentolamine group and hypoxia saline group. (6) In situ hybridization showed that mRNA of the three alpha1-AR subtypes located mainly in the artery and venous smooth muscle cells and endothelial cells.
This study suggested that alpha1-AR subtypes worked in the development of hypoxia pulmonary hypertension. More research on alpha1-AR subtypes may help the clinical treatment of pulmonary hypertension.
在低氧性肺动脉高压的发生发展过程中，肺组织中α1 - 肾上腺素能受体（α1 - adrenergic receptor，α1 - AR）的蛋白质和mRNA含量增加，而在此过程中α1 - AR亚型的变化未见专门报道。本研究旨在了解正常和低氧大鼠中α1 - AR亚型mRNA表达的数量和定位，以及酚妥拉明在低氧性肺动脉高压中的作用。
55只雄性Wistar大鼠随机分为5组：对照组（n = 10）、低氧2周组（n = 13）、低氧4周组（n = 10）、生理盐水对照组（n = 10）和低氧4周加酚妥拉明组（n = 12）。采用半定量逆转录聚合酶链反应（RT - PCR）检测各组α1 - AR亚型的mRNA表达。同时采用原位杂交检测正常大鼠肺组织中α1 - AR的定位。
（1）肺动脉压力随低氧时间延长而升高。（2）RT - PCR结果显示，各组中α1A - AR的mRNA表达量最多，α1B - AR次之，α1D - AR最少。（3）α1A - AR和α1B - AR mRNA的表达随低氧时间延长而增加，组间表达有差异。（4）α1D - AR的表达也随低氧时间延长而增加，但组间无差异。（5）酚妥拉明组与低氧生理盐水组三种亚型的mRNA量无差异。（6）原位杂交显示三种α1 - AR亚型的mRNA主要位于动脉和静脉平滑肌细胞及内皮细胞。
本研究提示α1 - AR亚型在低氧性肺动脉高压的发生发展中起作用。对α1 - AR亚型的进一步研究可能有助于肺动脉高压的临床治疗。
