Reduction in renal blood flow following acute increase in the portal pressure: evidence for the existence of a hepatorenal reflex in man?

Abstract

Background-To investigate the relation between changes in portal haemodynamics and renal blood flow (RBF) in patients with cirrhosis. Patients/Methods-Twenty patients with cirrhosis and transjugular intrahepatic portosystemic stent-shunts were divided into two groups which were well matched. At (RBF) and an increase in renal resistance.' 2 The reduction in RBF is accompanied by redistribution of intrarenal blood flow from the cortex to the medulla, even in patients without ascites,' and the hepatorenal syndrome is also characterised by constriction of the intralobular and the arcuate arteries.4There is considerable evidence of increased sympathetic nervous activity in patients with cirrhosis and sodium retention. Noradrenaline concentrations reflect sympathetic nervous activity and its concentration in the circulation is a result of overproduction rather than reduced clearance.5 Concentrations of noradrenaline are inversely related to sodium excretion.6 Lang et al,7 in an animal model, found an acute reduction in RBF following infusion of glutamine into the portal vein. The effect of the infusion was to induce acute hepatocyte swelling and portal hypertension. This was abolished following section of the hepatic vagal fibres and renal denervation. They proposed the existence of a hepatorenal axis controlled by a reflex arc, the afferent limb of which was the hepatic vagal innervation and the efferent limb was the renal sympathetic system. Transjugular intrahepatic portosystemic stent-shunt (TIPSS) is an interventional radiological technique that involves the creation of a fistulous communication between the hepatic and portal veins through the liver parenchyma; this track is supported by an expandable metal stent.

Hepatorenal Syndrome

“…A similar splenorenal reflex also is observed in animal models with portal hypertension (30). Support for this concept in humans comes from the studies by Jalan et al (31), who demonstrated acute reduction in RBF in a patient with cirrhosis after acute transjugular intrahepatic shunt insertion (TIPS) occlusion. In another study, lumbar sympathectomy increased GFR in five patients with HRS and GFR Ͻ25 ml/min but not in three others with GFR Ͼ25 ml/min, suggesting that renal sympathetic nerve activity contributes to renal vasoconstriction in a selected group of patients with HRS (32).…”

Interorgan ammonia and amino acid metabolism in metabolically stable patients with cirrhosis and a TIPSS

“…These flows are comparable with literature data. [18][19][20] Mean hepatic extraction of ICG was 0.288 Ϯ 0.049, which is higher than measured in patients with decompensated chronic and acute liver disease (0.054 Ϯ 0.085 21 ), supporting that our study population consisted of metabolically stable patients. In agreement, the body composition of the patients was similar to previous reports of patients with stable cirrhosis (Table 1).…”

Hyperdynamic circulation in portal-hypertensive rats is dependent on central c-fos gene expression

“…27 In addition, increased portal and sinusoidal pressure can elevate sympathetic nerve activity to the heart and kidney via a hepatic baroreceptor-dependent mechanism. [42][43][44] Colombato et al documented that systemic (iliac) vasodilatation precedes the development of hyperdynamic circulation in the PVS rat. 39 This observation raises the possibility that the initiating event is a primary peripheral vasodilatation, which activates the CNS to increase cardiac output and induce further vasodilatation.…”