Liefeldt L, Böcker W, Schönfelder G, Zintz M, Paul M
Max-Delbrück-Center for Molecular Medicine, Berlin, Germany.
J Cardiovasc Pharmacol. 1995;26 Suppl 3:S32-3.
We have established a transgenic rat model for the expression of the human endothelin-2 (ET-2). These animals exhibit overexpression of the transgene in tissues as well as in plasma. Despite these changes, blood pressure remains normal. To understand the regulatory mechanisms for normotension in the presence of increased ET-2 levels, we have investigated the ET system in more detail. We used competitive reverse transcription-polymerase chain reaction (RT-PCR) to evaluate possible overexpression or downregulation of endothelin A and B receptors at the mRNA level. PCR analyses revealed no significant differences of ETA and ETB receptor expression. In conclusion, the expression of human ET-2 in transgenic rats does not result in hypertension. Normotension in the transgenic animals is independent of ET receptor regulation. The reason for this may be counterregulation by other vasoactive systems, such as the NO system. Future studies will take this into account and will also concentrate on possible histomorphologic alterations caused by mitogenic properties of the endothelins.
我们建立了一种用于表达人内皮素 -2（ET -2）的转基因大鼠模型。这些动物在组织以及血浆中均表现出转基因的过表达。尽管有这些变化，但血压仍保持正常。为了解在ET -2水平升高情况下血压正常的调节机制，我们对ET系统进行了更详细的研究。我们使用竞争性逆转录 - 聚合酶链反应（RT - PCR）在mRNA水平评估内皮素A和B受体可能的过表达或下调情况。PCR分析显示ETA和ETB受体表达无显著差异。总之，人ET -2在转基因大鼠中的表达不会导致高血压。转基因动物的血压正常与ET受体调节无关。其原因可能是其他血管活性系统（如NO系统）的反调节作用。未来的研究将考虑到这一点，并且还将集中于内皮素的促有丝分裂特性可能引起的组织形态学改变。
