Portal Vein Arterialization for the Treatment of Post Resection Acute Liver Failure in the Rat

Systemic subchronic toxicity and comparison of four selenium nutritional supplements by 90-day oral exposure in Sprague-Dawley rats

To evaluate and compare the safety of four selenium supplements, namely Se-enriched peptides (SeP), yeast selenium (SeY), L-Se-methylselenocysteine (L-SeMc) and sodium selenite (Na2SeO3), the subchronic toxicity study was designed by 90-day gavage administration in Sprague-Dawley rats. The doses of SeP, SeY, L-SeMc and Na2SeO3 were 0.15, 0.30 and 0.60 mg/kg bw/day, with additional dose of 0.45 mg/kg L-SeMc (All dose calculated as Se). Symptoms like growling, hair loss and significant weight loss were found at 0.60 mg/kg of L-SeMc, but not in other groups. At the dose of 0.60 mg/kg, females in Na2SeO3, SeY and L-SeMc groups showed significant elevations in ALT and/or ALP. Pathologic manifestations such as bile duct hyperplasia and cholestasis were predominantly found in females at 0.6 mg/kg of L-SeMc and SeY groups, and in males at same dose of L-SeMc group showed marked testicular atrophy. 0.60 mg/kg of SeY and Na2SeO3, and 0.30, 0.45, 0.60 mg/kg of L-SeMc induced significant reductions in sperm motility rates, rapid movement and amount. In conclusion, the NOAEL of SeP, SeY, L-SeMc, Na2SeO3 was all 0.30 mg/kg for female, and 0.60, 0.30, 0.15 and 0.30 mg/kg for male respectively. Liver and reproductive organs are possible toxic target organs of hyper selenium.

A modified kidney-sparing portal vein arterialization model of heterotopic auxiliary liver transplantation increases liver IL-6, TNF-α, and HGF levels and enhances liver regeneration: an animal model

BACKGROUND AND AIM

The success of partial donor liver transplantation is affected by the implantation site of the donor liver and the vascular reconstruction approach. We investigated the effects of different donor liver implantation sites and vascular reconstruction approaches on liver regeneration using a rat kidney-sparing heterotopic auxiliary liver transplantation model, with portal vein arterialization (PVA).

METHODS

Sixty male Sprague-Dawley rats underwent end-to-end anastomosis of the donor liver portal vein and the right renal artery stent (control group), or end-to-side anastomosis of the donor liver portal vein and the left common iliac artery (experimental group).

RESULTS

The experimental group had significantly lower plasma levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST), total bilirubin, and cholinesterase than the control group (all, P < 0.05). The levels of tumor necrosis factor-α (TNF-α), interleukin 6 (IL-6), and hepatocyte growth factor (HGF) in the liver were significantly higher in the experimental group than that in the control group (all, P < 0.05). Hematoxylin and eosin (HE) staining of the liver tissue specimens indicated that the experimental group had greater hepatocyte regeneration compared to the control group.

CONCLUSIONS

The modified kidney-sparing PVA model of heterotopic auxiliary liver transplantation is more conducive to liver regeneration with quicker return of liver function.

Effects of Sub-Lethal Doses of Selenium Nanoparticles on the Health Status of Rats

Selenium nanoparticles (SeNPs) are fast becoming a key instrument in several applications such as medicine or nutrition. Questions have been raised about the safety of their use. Male rats were fed for 28 days on a monodiet containing 0.5, 1.5, 3.0 and 5.0 mg Se/kg. Se content in blood and liver, liver panel tests, blood glucose, total antioxidant capacity (TAC), the activity of superoxide dismutase (SOD) and glutathione peroxidase (GPx) were analysed. Liver and duodenum were subjected to histopathology examination. The weight gain of rats showed no differences between tested groups. Se content in blood was higher in all treated groups compared to the control group. The liver concentration of Se in the treated groups varied in the range from 222 to 238 ng/g. No differences were observed in the activity of AST (aspartate aminotransferase), ALP (alkaline phosphatase) and TAS (total antioxidant status). A significant decrease in ALT activity compared to the control group was observed in the treated groups. GPx activity varied from 80 to 88 U/mL through tested groups. SOD activity in liver was decreased in the SeNP-treated group with 5 mg Se/kg (929 ± 103 U/mL). Histopathological examination showed damage to the liver parenchyma and intestinal epithelium in a dose-dependent manner. This study suggests that short-term SeNP supplementation can be safe and beneficial in Se deficiency or specific treatment.

Partial Portal Vein Arterialization to Treat Toxic Acute Liver Failure in Elderly Rats

INTRODUCTION

Toxic acute liver failure can be fatal even after liver transplantation. Since there are data only in young rats, the aim of our study was to verify the effectiveness of the increase of oxygen to the liver by partial portal vein arterialization (PPVA) in elderly rats with acute liver failure induced by carbon tetrachloride (CCl₄) intoxication.

METHODS

Twenty elderly (30 months) Sprague-Dawley rats underwent a CCl₄ intoxication (5 mL/kg). Animals were divided after 24 hours (n = 10 per group) to either undergo PPVA (G1, treated group) or be untreated (G2, control group). PPVA consisted of a shunt between the left renal artery and splenic vein after nephrectomy and spelnectomy. The G2 group animals underwent nephrectomy and splenectomy only. The 10-day survival was evaluated. Before euthanasia, blood samples from the portal vein were detected for blood gas analysis. Liver injury was evaluated by the serum alanine aminotransferase (ALT) and prothrombin time levels. Histology was done to evaluate the liver necrosis. Hepatocyte regeneration was assessed by the mitotic index at immunohistochemistry.

RESULTS

The PPVA has resulted in a significant increase in the oxygen partial pressure and saturation in portal blood. A survival improvement at 10 days was registered in the PPVA-treated rats (90% vs 30%; P = .0065). After 24 hours from intoxication, ALT was high in both groups. A rapid decrease of ALT was observed in G1 as compared to G2. At the same time, livers showed a severe centrolobular necrosis. In the suviving G2 rats, a moderate necrosis was present, while only a mild necrosis was observed in the G1 rats. An higher mitotic index was detected in rats treated with PPVA.

CONCLUSIONS

In our experimental study, the presence of oxygenated blood in the portal venous system following the PPVA procedure had positive effects on liver regeneration and rats' survival. The PPVA treatment had beneficial effects in elderly rats.

Portal blood arterialization with an extracorporeal device to treat toxic acute hepatic failure in a swine model

PURPOSE

This study aimed to determine whether a controlled portal blood arterialization by a liver extracorporeal device (L.E.O2 NARDO) is effective in treating acute hepatic failure (AHF) induced through CCl4 administration in a swine model.

METHODS

20 swine with AHF induced by intraperitoneal injection of carbon tetrachloride (CCl4) in oil solution, were randomly divided into two groups: animals receiving L.E.O2 NARDO treatment 48 h after the intoxication (study group); animals sham operated 48 h after the intoxication (control group). Blood was withdrawn from the iliac artery and reversed in the portal venous system by an interposed extracorporeal device. Each treatment lasted 6 h. The survival was assessed at 5 days after L.E.O2 NARDO treatment or sham operation. In both groups blood samples were collected for biochemical analysis at different time points and liver biopsies were collected 48 h after intoxication and at sacrifice.

RESULTS

We observed decreased transaminases levels and a more rapid INR recovery in the study group, as compared to the control group. Eight animals of the study group vs. two animals of the control group survived at five days after surgery with a statistically significant difference (p<0.05). Liver biopsies performed at sacrifice showed a reduction of the damaged hepatic areas in the study group as compared to the control group.

CONCLUSIONS

Arterial blood supply in the portal system through the L.E.O2 NARDO device is easily applicable, efficacious, and safe in a swine model of AHF induced by CCl4 intoxication.

Partial portal vein arterialization in acute liver failure

Experimental studies have shown that increasing the oxygen supply to the liver through partial portal vein arterialization (PPVA) enhances liver regeneration after extensive liver resection or drug intoxication. In the last two decades, several PPVA procedures were performed in humans with the aim to prevent or treat acute liver failure (ALF) following major hepatobiliary surgery or other etiology. The aim of this review was to analyze literature data on PPVA and report our experimental and clinical experience of this procedure. In this setting, we report our positive experience in the realization and clinical application of an extracorporeal device able to increase the oxygenated blood delivered to the liver through the umbilical vein and to support liver function in a man subjected to an extended liver resection. PPVA procedure has shown promising results in the treatment of ALF following major hepatobiliary surgery or from other etiology. Moreover, less invasive approaches to PPVA demonstrated to be safe and efficacy. It is clear that further investigations must be done to fully understand the potentiality of PPVA as a strategy to treat ALF.

Nitric oxide reduces organ injury and enhances regeneration of reduced-size livers by increasing hepatic arterial flow

Background

Reduced-size livers suffer from portal hyperperfusion, diminished arterial blood flow and the risk of postoperative liver injury. The aim of this experimental study was to unravel the role of nitric oxide in this setting.

Methods

Rats underwent 85 per cent partial hepatectomy and either substitution of nitric oxide with molsidomine or inhibition of nitric oxide synthase (NOS) with NG-nitro-l-arginine methyl ester. Untreated hepatectomized animals served as controls and unresected animals as the sham group.

Results

Ultrasonic flowmetry following partial hepatectomy revealed a marked increase in portal venous inflow with a concomitant decrease in hepatic arterial inflow. Nitric oxide substitution counteracted the decline in hepatic arterial inflow and caused a significantly greater increase in cell proliferation after partial hepatectomy compared with control or NOS-inhibited animals. Hepatectomized animals further profited from nitric oxide substitution, as indicated by reduced aminotransferase release and improved liver function.

Conclusion

Nitric oxide improves the postoperative course of rats with reduced-size livers by modulating hepatic macrohaemodynamics and mediating regeneration and cytoprotection, but not by reducing hepatic hyperperfusion and the accompanying sinusoidal shear stress.

Portal vein arterialization in hepatobiliary surgery and liver transplantation

We reviewed the literature reports and our personal experience on partial portal vein arterialization (PPVA) to prevent and treat acute liver failure (ALF) following major hepatobiliary surgery or another etiology. Experimental studies in rats have assessed the efficacy of PPVA in treatment of ALF induced by extended resections in normal or fatty livers or in toxic carbon-tetrachloride damage. The treated groups showed greater survival and faster recovery of liver function. Among 11 clinical cases reported in the literature, PPVA was performed in four cases to prevent and in seven cases to treat ALF. Eight patients survived, showing rapid recovery of liver function and resolution of the clinical condition. This relatively simple procedure has shown itself able to promote liver regeneration. The PPVA procedure has shown itself to be safe and simple as well as to offer a promising approach to the failing liver.