Nevalainen M T, Valve E M, Ingleton P M, Nurmi M, Martikainen P M, Harkonen P L
Institute of Biomedicine, Department of Anatomy, University of Turku, Finland.
J Clin Invest. 1997 Feb 15;99(4):618-27. doi: 10.1172/JCI119204.
Prolactin is widely expressed in different tissues, and it is presumed to have both local and systemic actions. In males it is known to influence reproductive functions but the significance and mechanisms of prolactin action in male accessory reproductive tissues are poorly understood. Here we show that prolactin acts as a direct growth and differentiation factor for human prostate, as measured by changes in DNA synthesis and epithelial morphology of organ cultures. Furthermore, we report the expression in human prostate of a short prolactin receptor form in addition to the long form, based upon ligand cross-linking studies and RT-PCR analysis of mRNA expression. The highest density of prolactin receptors was detected in the secretory epithelial cells by immunohistochemistry. Finally, we report that prolactin is locally produced in human prostate epithelium, as evidenced by marked prolactin immunoreactivity in a significant portion of prostate epithelial cells, with parallel expression of prolactin mRNA in human prostate. Collectively, these data provide significant support for the existence of an autocrine/paracrine loop of prolactin in the human prostate and may shed new light on the involvement of prolactin in the etiology and progression of neoplastic growth of the prostate.
催乳素在不同组织中广泛表达，推测其具有局部和全身作用。已知在男性中它会影响生殖功能，但对催乳素在男性附属生殖组织中的作用意义和机制了解甚少。在此我们表明，通过器官培养物中DNA合成和上皮形态的变化来衡量，催乳素作为人前列腺的直接生长和分化因子。此外，基于配体交联研究和mRNA表达的RT-PCR分析，我们报告除了长形式外，人前列腺中还存在一种短形式的催乳素受体表达。通过免疫组织化学在分泌上皮细胞中检测到催乳素受体的最高密度。最后，我们报告催乳素在人前列腺上皮中局部产生，这在很大一部分前列腺上皮细胞中显著的催乳素免疫反应性以及人前列腺中催乳素mRNA的平行表达中得到证明。总体而言，这些数据为人类前列腺中催乳素自分泌/旁分泌环的存在提供了重要支持，并可能为催乳素参与前列腺肿瘤生长的病因和进展提供新的线索。
