Leung P S, Chan W P, Wong T P, Sernia C
Department of Physiology, Faculty of Medicine, The Chinese University of Hong Kong, Shatin, NT, Hong Kong.
J Endocrinol. 1999 Jan;160(1):13-9. doi: 10.1677/joe.0.1600013.
The possibility of an intrinsic renin-angiotensin system (RAS) in the pancreas has been raised by previous studies in which immunohistochemical examination showed the presence of angiotensin II and its receptor subtypes, type 1 (AT1) and type 2 (AT2). In the present study, gene expression of several key RAS components was investigated by reverse-transcription PCR. mRNA expression for angiotensinogen, renin and angiotensin II receptor subtypes, AT1a, AT1b and AT2 was shown. The presence of angiotensinogen protein, the mandatory component for an intrinsic RAS, was demonstrated by Western blotting and localized by immunohistochemistry to the epithelia and endothelia of pancreatic ducts and blood vessels respectively. Immunoblot analysis detected a predominant protein band of about 60 kDa in the pancreas. This was consistent with the predicted value for angiotensinogen as reported in other tissues. Together with previous findings, the present study shows that the rat pancreas expresses the major RAS component genes, notably angiotensinogen and renin, required for intracellular formation of angiotensin II. The data support the notion of an intrinsic RAS in the rat pancreas which may play a role in the regulation of pancreatic functions.
先前的研究提出胰腺中可能存在内源性肾素-血管紧张素系统（RAS），这些研究通过免疫组织化学检查显示了血管紧张素II及其受体亚型1型（AT1）和2型（AT2）的存在。在本研究中，通过逆转录PCR研究了几种关键RAS成分的基因表达。显示了血管紧张素原、肾素和血管紧张素II受体亚型AT1a、AT1b和AT2的mRNA表达。通过蛋白质印迹法证实了内源性RAS的必需成分血管紧张素原蛋白的存在，并通过免疫组织化学分别将其定位在胰管和血管的上皮和内皮中。免疫印迹分析在胰腺中检测到一条约60 kDa的主要蛋白条带。这与其他组织中报道的血管紧张素原预测值一致。与先前的研究结果一起，本研究表明大鼠胰腺表达血管紧张素II细胞内形成所需的主要RAS成分基因，特别是血管紧张素原和肾素。这些数据支持大鼠胰腺中存在内源性RAS的观点，其可能在胰腺功能调节中发挥作用。
