The role of prostatic interstitium for expression of the obstructive symptom and prostatic growth of benign prostatic hyperplasia

肾上腺素能刺激通过α_l肾上腺素能受体引起增生组织收缩，药理学研究表明存在其亚型。近年来，利用分子生物学技术，已发现并克隆了a_<la>，a_<lb>，a_<ld>三种亚型。利用这些亚型的探针，我们用原位杂交方法证实了它们在良性前列腺增生（BPH）和非BPH组织中的表达。为了定量这些亚型之间的比例，在这些情况下，也尝试了RNA酶保护试验。a_<la>和a_<ld>肾上腺素受体在间质平滑肌中广泛表达，而在腺上皮细胞中则无表达。相反，α-<lb>肾上腺素受体的识别能力很弱。在所有检测的组织样本中，主要亚型mRNA为alpha 1a。BPH样本中alpha 1 mRNA的总丰度是非BPH样本中的6倍以上，alpha 1a mRNA表达的增加占这种增加的大部分（非BPH中的8倍）。alpha 1b的丰度在BPH和非BPH样品之间没有变化，并且BPH样品中a ld的丰度是非BPH样品中的约三倍。在非BPH样本中，亚型mRNA的丰度比，α 1a：α 1b：α 1d为63：8：29，在BPH样本中为85：1：14。

The adrenergic stimulation induces the contraction of the hyperplastic tissues via a_l adrenoceptor and pharmacological studies suggested the existence of its subtypes. Recently three subtypes (a_<la>, a_<lb>, a_<ld>) have been detected and cloned using molecular biologic technique. Using the probes for these subtypes, we demonstrated their expression in cases with benign prostatic hypertplasia (BPH) and non-BPH tissues with in situ hybridization method. To quantify the ratio among these subtypes, RNase protection assay was also attempted in these cases. The expression of the a_<la> and a_<ld> adrenoceptors was diffusely reconginzed in the smooth muscles in the interstitium, while not in the glandular epithelial cells. On the contrary, the a_<lb> adrenoceptor was very weakly recognized. In all tissue samples tested, the predominant subtype mRNA was alpha1a. The total abundance of alpha1 mRNA in BPH samples was over six times that in non-BPH samples, the increased expression of alpha1a mRNA accounting for most of this increase (eight times that in non-BPH). The abundance of alpha1b did not vary between BPH and non-BPH samples, and the abundance of a ld in BPH samples was about three times in non-BPH samples. The ratio of the abundance of the subtype mRNAs, alpha1a : alpha1b : alpha1d was 63 : 8 : 29 in non-BPH samples and 85 : 1 : 14 in BPH samples.