Heller J, Schepke M, Gehnen N, Molderings G J, Müller A, Erhard J, Spengler U, Sauerbruch T
Department of General Internal Medicine, University of Bonn, Germany.
Gastroenterology. 1999 Feb;116(2):387-93. doi: 10.1016/s0016-5085(99)70136-8.
BACKGROUND & AIMS: Patients with cirrhosis are characterized by a reduced splanchnic vascular resistance and a hyporeactivity to adrenergic vasoconstrictors. So far, their adrenergic splanchnic vascular responsiveness has not been evaluated in vitro. We compared responses to alpha1- and beta2-adrenoceptor stimulation of hepatic arteries and portal veins of patients with cirrhosis undergoing transplantation with those of organ donors.
Isometric contractions of endothelium-denuded vessel rings were induced cumulatively by methoxamine and relaxations by isoproterenol. Results are expressed as percentage of the contraction obtained by 85 mmol/L KCl or of the relaxation obtained by 100 micromol/L papaverine, respectively.
Maximal methoxamine-induced contractions were reduced in cirrhotic hepatic arteries (cirrhosis, 51.8% +/- 6.8%; donor, 89.9% +/- 6.6%; P < 0.01) and portal veins (cirrhosis, 49.2% +/- 6.4%; donor, 94.0% +/- 5.3%; P < 0.01). In cirrhosis, isoproterenol induced a less marked relaxation of hepatic arteries (cirrhosis, 46.6% +/- 3.2%; donor, 100.3% +/- 4.4%; P < 0. 01) but an increased relaxation of portal veins (cirrhosis, 41.9% +/- 6.2%; donor, 26.2% +/- 2.8%; P < 0.01).
In cirrhosis, endothelium-free hepatic arteries are hyporeactive to alpha1- and beta2-adrenoceptor agonists, and portal veins are hyporeactive to alpha1- but hyperreactive to beta2-adrenoceptor agonists. These findings support the in vivo findings of a hyporesponsiveness to adrenergic vasoconstrictors in patients with cirrhosis.
肝硬化患者的特点是内脏血管阻力降低，对肾上腺素能血管收缩剂反应低下。迄今为止，尚未在体外评估他们的肾上腺素能内脏血管反应性。我们比较了接受移植的肝硬化患者与器官供体的肝动脉和门静脉对α1-和β2-肾上腺素能受体刺激的反应。
用甲氧明累积诱导去内皮血管环的等长收缩，用异丙肾上腺素诱导舒张。结果分别表示为85 mmol/L氯化钾引起的收缩或100 μmol/L罂粟碱引起的舒张的百分比。
肝硬化患者肝动脉中，甲氧明诱导的最大收缩降低（肝硬化组为51.8%±6.8%；供体组为89.9%±6.6%；P<0.01），门静脉中也是如此（肝硬化组为49.2%±6.4%；供体组为94.0%±5.3%；P<0.01）。在肝硬化患者中，异丙肾上腺素引起的肝动脉舒张不太明显（肝硬化组为46.6%±3.2%；供体组为100.3%±4.4%；P<0.01），但引起的门静脉舒张增加（肝硬化组为41.9%±6.2%；供体组为26.2%±2.8%；P<0.01）。
在肝硬化患者中，无内皮的肝动脉对α1-和β2-肾上腺素能受体激动剂反应低下，门静脉对α1-肾上腺素能受体激动剂反应低下，但对β2-肾上腺素能受体激动剂反应亢进。这些发现支持了肝硬化患者体内对肾上腺素能血管收缩剂反应低下的发现。
