Yang M C, Yu P C, Tu M S, Lay C S, Hong C Y, Chou C K, Chen C F, Kuo J S
Department of Medical Research, Veterans General Hospital, Taipei, Taiwan, R.O.C.
Life Sci. 1990;46(26):1929-36. doi: 10.1016/0024-3205(90)90508-o.
Endothelin is a vasoconstrictor peptide which has recently been isolated and sequenced from the vascular endothelial cells. It was reported to increase blood pressure in vivo and produce a prolonged contraction with a slow onset in vitro. The purpose of this study was to investigate whether endothelin can lower the portal pressure as another endogenous vasoconstriction peptidevasopressin (AVP) can. Heart rate, systemic blood pressure, portal pressure, and portal vein blood flow were measured. Effects of endothelin on these parameters were compared with those of AVP. Endothelin 10(-10) mol/Kg significantly decreased all of the parameters mentioned. At the higher dose (5 x 10(-10) mol/Kg), however, the portal pressure and blood pressure were increased and portal vein blood flow was unchanged. On the other hand, AVP decreased the portal pressure and portal vein blood flow but elevated the systemic blood pressure. In vitro experiments revealed that endothelin contracted both tail artery and portal vein of rat and vasopressin contracted only tail artery. We concluded that although both are endogenous vasoconstricting peptides, endothelin and AVP affect differently on arterial and venous vascular beds as well as on portal pressure.
内皮素是一种血管收缩肽，最近已从血管内皮细胞中分离出来并进行了测序。据报道，它在体内可升高血压，在体外可产生起效缓慢的长时间收缩。本研究的目的是探讨内皮素是否能像另一种内源性血管收缩肽血管加压素（AVP）那样降低门静脉压力。测量了心率、体循环血压、门静脉压力和门静脉血流量。将内皮素对这些参数的影响与AVP的影响进行了比较。内皮素10（-10）mol/Kg可显著降低上述所有参数。然而，在较高剂量（5×10（-10）mol/Kg）时，门静脉压力和血压升高，门静脉血流量未改变。另一方面，AVP降低了门静脉压力和门静脉血流量，但升高了体循环血压。体外实验表明，内皮素可使大鼠尾动脉和门静脉收缩，而血管加压素仅使尾动脉收缩。我们得出结论，尽管内皮素和AVP都是内源性血管收缩肽，但它们对动脉和静脉血管床以及门静脉压力的影响不同。
