Pedersen L G, Zhao J, Yang J, Thomsen P D, Gregersen H, Hasenkam J M, Smerup M, Pedersen H D, Olsen L H
Department of Basic Animal and Veterinary Sciences, The Royal Veterinary and Agricultural University, 7 Groennegaardsvej, DK-1870 Frederiksberg, Copenhagen, Denmark.
Res Vet Sci. 2007 Apr;82(2):232-8. doi: 10.1016/j.rvsc.2006.07.009. Epub 2006 Sep 29.
The aim of this study was to evaluate the effect of mechanical stretch on the expression of ET-1 and ET(A)- and ET(B)-receptors in porcine mitral valve leaflets. Leaflet segments from 10 porcine mitral valves were exposed to a static stretch load of 1.5 N for 3.5h in buffer at 37 degrees C together with matching control segments. Subsequently, the mRNA expression of ET-1, ET(A)-R and ET(B)-R was measured by real-time RT-PCR in the chordal insertion areas. The analyses showed an increased transcription of ET(B)-receptors in stretch-exposed leaflet segments compared to unstretched segments median 2.23 (quartiles 1.37 and 2.70) vs. median 1.56 (quartiles 1.38 and 2.17, P=0.03) whereas the mRNA expression of ET(A)-receptors (P=0.90) and ET-1 (P=0.51) remained unchanged. Stretch increased the expression of ET(B)-receptors in porcine mitral valve leaflets. The finding could lead to a better understanding of the pathogenesis of myxomatous mitral valve disease.
本研究的目的是评估机械拉伸对猪二尖瓣小叶中内皮素-1（ET-1）、ET(A)受体和ET(B)受体表达的影响。将来自10个猪二尖瓣的小叶节段在37℃的缓冲液中与匹配的对照节段一起暴露于1.5 N的静态拉伸负荷下3.5小时。随后，通过实时逆转录聚合酶链反应（RT-PCR）在腱索插入区域测量ET-1、ET(A)受体和ET(B)受体的mRNA表达。分析显示，与未拉伸节段相比，拉伸暴露的小叶节段中ET(B)受体的转录增加，中位数为2.23（四分位数为1.37和2.70），而未拉伸节段的中位数为1.56（四分位数为1.38和2.17，P=0.03），而ET(A)受体（P=0.90）和ET-1（P=0.51）的mRNA表达保持不变。拉伸增加了猪二尖瓣小叶中ET(B)受体的表达。这一发现可能有助于更好地理解黏液瘤样二尖瓣疾病的发病机制。
