Stability of a rat model of prehepatic portal hypertension caused by partial ligation of the portal vein

Abstract

AIM:To study the stability of portal hypertension (PHT) caused by partial ligation of the portal vein ligation (PVL) in a rat model. METHODS:Thirty male adult Wistar rats were divided into two groups: 10 in Group Ⅰ received a sham operation; and 20 in Group Ⅱ received partial PVL. Portal vein pressure (PVP) was measured at four time periods: before ligation, 2 wk, 6 wk and 10 wk postsurgery. Portal venography, blood sampling and liver and spleen pathological examinations were conducted at 10 wk after surgery. RESULTS:The PVP was 9.15 ± 0.58 cmH2O before ligation, and increased to 17.32 ± 0.63 cmH2O 2 wk after PVL. By repeat measurement of the PVP in each rat, it was shown to remain elevated for 10 wk. There were no significant differences in the pressure measurements at 2 wk, 6 wk and 10 wk. Varices were found mainly in the mesenteric vein 2 wk after PVL, which were more obvious later, while these manifestations were similar at week 6 and week 10. Portal venography demonstrated the varices and collaterals. There was no significant change in liver pathology. The volume of the spleen was enlarged 2-fold after ligation, and the sinus of the spleen was enlarged due to congestion. Significant sinus endothelial cell proliferation was observed, but no evidence of hypersplenia was found on hemogram and biochemical examination. CONCLUSION:T he s e f indings s ugge s t t h a t a satisfactory prehepatic PHT rat model can be obtained by partial ligation of the portal vein, and this PHT rat model was stable for at least 10 wk.

Constriction rate variation produced by partial ligation of the portal vein at pre-hepatic portal hypertension induced in rats

“…Wen et al 14 estimated a deviation of approximately 95% of the portal blood flow when the partial ligature of the rat's portal vein is performed, with venous dilations in the mesenteric vein appearing two weeks after this ligature. This paper found significant dilatation of the superior mesenteric vein and its tributaries, both two and four weeks after the constriction of the portal vein diameter, as well as numerous dilated, congested and tortuous vessels were observed throughout the peritoneal cavity, mesentery, omentum and abdominal wall of studied animals.…”

“…The measurement of portal vein below the ligature made in the first operation was performed; the portal vein was cut above the ligature for evidence of blood flow, demonstrating the absence of its complete obstruction. The evaluation of the reduction percentage in the diameter of the portal vein was done with mathematical formula that defines the rate of the vessel constriction (1 - π r 2 /π R 2 ) x 100%), where the smallest radius® corresponds to the catheter and the largest® to the animal's portal vein 13 , 14 .…”

“…The experimental model with the partial portal vein ligature does not compromise the hepatic function significantly 10 , 14 , leading to a peak of pressure in the first 24 h, which stabilizes twice as much the initial values after 15 days, with the dilation of the splanchnic vessels, keeping itself stable even after the appearance of this collateral circulation 14 with the posterior adaptation to the prolonged decrease of the blood flow through the portal vein 13 , 16 .…”

Protection of estrogen in portal hypertension gastropathy: an experimental model

“…A previous work by our group (26) and other authors (6,34,38,40) showed that on day 15 post-PPVL there is a significant increase in PP in all animals. In the present study with female rats subjected to PPVL, the intact rats showed no significant increase in PP, but in the castrated rats PP was significantly increased (P<0.05) (Figure 2).…”

Effect of experimentally induced portal hypertension on the fundic mucosa of adult male albino rats and the possible protective role of quercetin supplementation

“…Moreover, PHT impairs gastric mucosal healing in response to injury by noxious factors such as alcohol [5]. Introduction started from the eighth day after surgery [18]. At the end of the experiments, 10 weeks after PPVL, the rats were anesthetized for measurement of portal venous pressure (PVP), histological and biochemical studies of stomach fundus mucosa samples, and blood analysis.…”