Hemodynamic effects of calibrated stenosis of the superior mesenteric artery in conscious rats with portal vein stenosis

Because superior mesenteric arterial blood flow is increased in portal hypertension and plays a role in elevated portal pressure, mechanical reduction of artery diameter should induce decreases in portal pressure and superior mesenteric arterial blood flow. In this study, calibrated superior mesenteric artery stenosis (induced with a 22‐gauge needle) was performed in rats simultaneously with portal vein stenosis or 2 wk after creation of portal vein stenosis. Hemodynamic studies were performed 3 wk after induction of portal vein stenosis in conscious, unrestrained rats. At that time, neither weight loss nor digestive tract alterations were observed in rats with arterial stenosis. In neither group of rats with arterial stenosis was portal tributary blood flow significantly different from that of normal rats; nor was it significantly lower than in rats with portal vein stenosis without arterial stenosis. In both groups of rats with arterial stenosis, portal pressure was significantly lower (12.1 ± 1.6 mm Hg and 12.5 ± 1.8 mm Hg, respectively) than in rats subjected to portal vein stenosis (15.4 ± 1.5 mm Hg) but significantly higher than in controls (7.2 ± 1.0 mm Hg). In rats with arterial stenosis, cardiac index was also significantly lower than that in rats with portal vein stenosis but higher than that in controls. In conclusion, this study shows that both early and late superior mesenteric artery stenosis significantly reduce the degree of portal hypertension and the hyperkinetic state of rats with extrahepatic portal hypertension. Thus we can speculate that superior mesenteric artery stenosis might provide a new therapeutic approach for portal hypertension.

[1]  D. Lebrec,et al.  Early chronic administration of propranolol reduces the severity of portal hypertension and portal-systemic shunts in conscious portal vein stenosed rats. , 1991, Journal of hepatology.

[2]  Han Lin,et al.  Prevention of portal hypertension and portosystemic shunts by early chronic administration of clonidine in conscious portal vein‐stenosed rats , 1991, Hepatology.

[3]  P. Wolters,et al.  Regulation of ion transport in porcine gallbladder: effects of VIP and norepinephrine. , 1989, The American journal of physiology.

[4]  D. Lebrec.  Drugs for portal hypertension , 1987 .

[5]  D. Valla,et al.  Role of portasystemic shunts in the hyperkinetic circulation of the portal hypertensive rat. , 1986, The Journal of laboratory and clinical medicine.

[6]  R. Groszmann,et al.  Hemodynamic Factors Involved in the Development and Rupture of Esophageal Varices: A Pathophysiologic Approach to Treatment , 1986, Seminars in liver disease.

[7]  C. O. Lee.  200 years of digitalis: the emerging central role of the sodium ion in the control of cardiac force. , 1985, The American journal of physiology.

[8]  D. Granger,et al.  "Forward" and "backward" flow mechanisms of portal hypertension. Relative contributions in the rat model of portal vein stenosis. , 1985, Gastroenterology.

[9]  J. Bosch.  Effect of pharmacological agents on portal hypertension: a haemodynamic appraisal. , 1985, Clinics in gastroenterology.

[10]  D. Lebrec,et al.  Changes in splanchnic blood flow in portal hypertensive rats , 1982, European journal of clinical investigation.

[11]  R. Groszmann,et al.  Portal pressure reduction induced by partial mechanical obstruction of the superior mesenteric artery in the anesthetized dog. , 1978, Gastroenterology.

[12]  D. McDevitt,et al.  Simultaneous measurement of cardiac output and its distribution with microspheres in the rat. , 1976, Cardiovascular research.