Distorted microangioarchitecture and impaired angiogenesis in gastric mucosa of portal hypertensive rats.
OBJECTIVE
Portal hypertensive (PHT) gastropathy is now recognized as a distinct entity, but the size of microvessels has been a subject of controversy. Angiogenesis in PHT gastric mucosa has not been explored. The aim of this study was to examine the angioarchitecture of PHT and non-PHT gastric mucosae before and after ethanol-induced injury utilizing microvascular cast techniques.


METHODS
Portal hypertension was produced by staged portal vein occlusion. Fourteen days later, gastric vascular casts were made in both PHT and control (sham-operated) rats by Mercox resin infusion. After tissue dissolution, casts were examined under a scanning electron microscope. To examine angiogenesis in injured gastric mucosa, the above study was repeated in PHT and control rats 18 hours after intragastric administration of 100% ethanol.


RESULTS
The capillary casts in PHT gastric mucosa (mean diameter, 6.3 +/- 0.03 microns) were significantly narrower than those of controls (mean diameter, 8.6 +/- 0.02 microns; P < 0.01). After ethanol injury, 5.5% +/- 0.3% of microvessels in gastric mucosa of sham-operated rats contained buds, showing angiogenesis. In contrast, PHT gastric mucosa had a paucity of capillary angiogenesis (buds in only 0.4% +/- 0.2% of microvessels; P < 0.01 vs. control).


CONCLUSIONS
This study shows prominent persistent abnormalities in the microangioarchitecture of PHT gastric mucosa. Moreover, PHT gastric mucosal microvessels have a marked impairment of angiogenic response to ethanol injury.
Ichikawa
Y
Y
Yokohama City University School of Medicine, Japan.
Tarnawski
A
A
Sarfeh
I J
IJ
Ishikawa
T
T
Shimada
H
H
D000818:Animals; D001808:Blood Vessels / Q000187:drug effects / Q000648:ultrastructure; D016319:Corrosion Casting; D000431:Ethanol / Q000008:administration & dosage / Q000494:pharmacology; D005753:Gastric Mucosa / Q000098:blood supply* / Q000187:drug effects; D006975:Hypertension, Portal / Q000473:pathology* / Q000503:physiopathology*; D008297:Male; D008833:Microcirculation / Q000187:drug effects; D008855:Microscopy, Electron, Scanning; D009389:Neovascularization, Pathologic / Q000473:pathology*; D051381:Rats; D017207:Rats, Sprague-Dawley
D000431:Ethanol