Title: Role of endothelin‐1 in congestive gastropathy in portal hypertensive rats
Abstract: Abstract Background : The aim of this study was to determine the role of endothelin (ET)‐1 in portal hypertensive gastropathy (PHG) under portal hypertension, in order to investigate whether the ET A/B receptor inhibitor improves the permeability of gastric mucosal microvessels in PHG. Methods and Results : Portal hypertensive rats (PVL) and sham‐operated rats (CTR) were prepared and then the concentration of plasma ET‐1 was measured and the vasopressor response to ET‐1 was compared between the two groups. The plasma ET‐1 levels in PVL increased significantly compared with CTR; however, the vasopressor response to ET‐1 in PVL decreased more than in CTR. Next, the portal venous pressure was measured in both CTR and PVL pretreated with or without a nitric oxide (NO) synthase inhibitor, N G ‐nitro‐ L ‐arginine methyl ester ( L ‐NAME), before the injection of ET‐1. The portal venous pressure of PVL after receiving ET‐1 and being pretreated with L ‐NAME significantly increased in comparison to the pressure of PVL treated with ET‐1 alone (without L ‐NAME). Moreover, Evans‐Blue was injected into each rat and the absorbancy of the gastric contents was measured. The absorbancy of Evans‐Blue in PVL increased significantly compared with CTR; however, the absorbancy in PVL + ET A/B receptor inhibitor (Ro47–0203) decreased significantly more than in PVL. Conclusions : This study showed that ET‐1 is a potent vasoconstrictive substance that also has a transitory vasodilative response through NO induced by ET‐1 in portal hypertension. In addition, it was found that the vascular permeability of the gastric mucosa increased in portal hypertension and that Ro47‐0203 inhibited the hyper‐permeability. Accordingly, ET‐1 may, thus, play an important role in the development of PHG through NO induced by ET‐1. Ro47‐0203 may, therefore, be a useful substance for improving PHG in portal hypertension.
Publication Year: 2000
Publication Date: 2000-02-01
Language: en
Type: article
Indexed In: ['crossref', 'pubmed']
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Cited By Count: 23
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