Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “LIVER CIRCULATION”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 523 records · Page 29Linked to original sources
PubMed2001

Minimal protection of the liver by ischemic preconditioning in pigs.

Ischemic preconditioning (IP) protects the rat liver. In pigs, in which hepatic tolerance to ischemia is similar to that in humans, information on IP is lacking. Therefore, in enflurane-anesthetized pigs, hepatic vessels were occluded for 120 min (protocol 1) or 200 min (protocol 2) without (control) and with IP (3 times 10 min ischemia-reperfusion each). In protocol 1, cumulative bile flow (CBF) during reperfusion was greater in IP (47.3 +/- 5.2 ml/8 h) than in control (17.1 +/- 7.8 ml/8 h, P < 0.05). ATP content tended to recover toward normal during reperfusion in IP, whereas it remained at ischemic levels in control. Serum enzyme concentrations increased similarly during reperfusion, and <1% hepatocytes were necrotic or stained terminal deosynucleotidyl transferase-mediated dUTP nick-end labeling-positive in control and IP groups. In protocol 2, no differences in CBF, ATP, or serum enzyme concentrations during reperfusion were measured between control and IP groups, except for a somewhat reduced lactate dehydrogenase in IP. The number of necrotic or terminal deosynucleotidyl transferase-mediated dUTP nick-end labeling-positive hepatocytes tended to be greater in the IP than the control group. Thus IP provides some functional protection against reversible ischemia but no protection during prolonged ischemia in pigs.

Adenosine Triphosphate↗
PubMed1984

The effect of continuous vasopressin infusion on splanchnic blood flow, liver function, and portal and central venous pressures in patients with cirrhosis.

Continuous vasopressin infusion has been shown to control bleeding from oesophageal varices in patients with cirrhosis of the liver. The mortality, however, has not been changed. To investigate whether reduction of portal blood flow over a period of hours deteriorates the liver function, we measured the splanchnic blood flow and galactose and oxygen consumption in five cirrhotic patients during liver vein catheterization. Vasopressin was given as a continuous infusion of 0.2 units per min for three h. The splanchnic blood flow was reduced to 70% of control values and remained so throughout the infusion. After three h no impairment of the liver function was found. The wedged hepatic pressure (portal pressure) rose slightly, probably due to the increase of the central venous pressure reflecting impaired cardiac function. The reported beneficial effect of vasopressin on varix bleeding probably depends on the reduced portal flow per se.

Adult↗
PubMed1993

No net splanchnic release of glutathione in man during N-acetylcysteine infusion.

Glutathione and amino acid concentrations were measured in arterial and hepatic vein plasma in four healthy volunteers and two patients with cirrhosis. There was no significant splanchnic efflux of glutathione (95% confidence limits, -0.501 to 0.405 mumol/min). After infusion of N-acetylcysteine (NAC) in a high dose (150 mg/kg body weight primer plus 15 mg/(h x kg BW), corresponding to treatment of acetaminophen overdose, there was no change in the splanchnic glutathione efflux (95% confidence limits, -0.531 to 0.375 mumol/min). NAC increased hepatic plasma flow rate from 0.90 +/- 0.531 min-1 to 0.97 +/- 0.11 (mean +/- SEM; p < 0.05). The effects of NAC treatment on plasma amino acids corresponded to an increased load on hepatic metabolic N conversion and transamination among nonessential amino acids. Splanchnic uptake of serine, alanine, cystine, isoleucine, and phenylalanine increased after NAC compatible with stimulated hepatic glutathione synthesis. In contrast to the rat, plasma glutathione in man probably originates mainly from extrahepatic tissues.

Acetylcysteine↗
PubMed1991

Hemodynamic study during transdermal application of nitroglycerin tape in patients with cirrhosis.

We studied 14 patients with portal hypertension and cirrhosis using portal and hepatic vein catheterizations to determine the effects of transdermal application of nitroglycerin tape (containing 10 mg of nitroglycerin and capable of releasing 6 to 7 mg of nitroglycerin in 12 hr) on splanchnic hemodynamics. Patients randomly received nitroglycerin (n = 7) or a placebo (n = 7). No significant changes were observed after the administration of the placebo. In contrast, transdermal nitroglycerin caused a significant reduction in portal pressure, as evaluated by measurements of the portal venous pressure gradient (-22%, p less than 0.01). The reduction of portal pressure was due to a decrease in the portal venous pressure, with no changes in the free hepatic venous pressure. Despite the fall in portal pressure, the hepatic blood flow was maintained. These findings suggest that transdermal nitroglycerin could be potentially useful in the treatment of portal hypertension associated with cirrhosis.

Administration, Cutaneous↗
PubMed1995

Endothelin-1 and -3 plasma concentrations in patients with cirrhosis: role of splanchnic and renal passage and liver function.

Increased as well as decreased plasma concentrations of the endothelins, endogenous vasoactive peptides, have been reported in cirrhosis. This might be caused by alterations of hepatic or renal clearance or release. Therefore, the aim of the current study was to investigate the influence of splanchnic and renal passage and of liver function on plasma concentrations of endothelin-1 (ET-1) and endothelin-3 (ET-3) in patients with cirrhosis compared with controls. Eighteen patients with cirrhosis and 8 normotensive controls of similar age were investigated. Arterial and venous plasma samples were obtained simultaneously, and ET-1 and ET-3 concentrations were determined in extracted plasma by two separate radioimmunoassays. Arterial as well as hepatic and renal venous concentrations of ET-1 in cirrhosis (17.8 +/- 0.8 pg/mL, 19.1 +/- 0.9 pg/mL, and 16.8 +/- 0.8 pg/mL) were significantly (P < .001) higher than in controls (9.2 +/- 1.7 pg/mL, 9.0 +/- 2.0 pg/mL, and 8.4 +/- 1.9 pg/mL, respectively). The same held true for the corresponding ET-3 plasma concentrations in cirrhosis (19.3 +/- 1.6 pg/mL, 20.5 +/- 1.5 pg/mL, and 18.4 +/- 1.5 pg/mL, respectively) compared with controls (11.1 +/- 1.8 pg/mL, 11.3 +/- 1.5 pg/mL, and 10.1 +/- 1.7 pg/mL, respectively; P < .01). There was a significant (P < .05) renal net extraction of ET-1 and ET-3 in cirrhosis. In contrast, a significant (P < .05) net release of ET-1 and ET-3 (2.40 +/- 0.80 ng/min and 1.75 +/- 1.16 ng/min) during splanchnic passage was observed in cirrhosis, but not in controls (-0.24 +/- 0.51 ng/min, and -0.46 +/- 0.64 ng/min).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1996

Assessment of functional liver mass and plasma flow in acromegaly before and after long-term treatment with octreotide.

Functional liver mass and functional liver plasma flow (FLPF) were assessed in 11 patients with clinical features of acromegaly by determining galactose elimination capacity (GEC) and extrarenal clearance of sorbitol, before and 5 to 7 months after treatment with the long-acting somatostatin analog, octreotide (150 to 600 micrograms/d in three subcutaneous injections). Growth hormone (GH) and insulin-like growth factor-I (IGF-I) levels, as well as liver size by ultrasound, were also recorded. Baseline GEC was increased in every patient but one, for a mean of 0.78 +/- 0.10 g/min (normal, 0.53 +/- 0.07; P < .01). At reevaluation after 5 to 7 months of octreotide treatment, a significant reduction of GEC was observed (0.62 +/- 0.08 g/min, P < .001). Changes of GEC paralleled those of GH (38.6 +/- 34.4 v 11.7 +/- 15.2 micrograms/L, P < .01) and IGF-I (5.0 +/- 1.7 v 2.7 +/- 2.2 U/ml, P < .001). Significant correlations were found between GEC and GH (r = .50, P < .05) and between GEC and IGF-I (r = .55, P < .01). FLPF, assessed by extrarenal clearance of sorbitol, was within the normal limit in all cases (0.98 +/- 0.19 v 0.97 +/- 0.12 L/min, NS) and remained normal after 5 to 7 months of octreotide treatment (0.99 +/- 0.11 L/min). Hepatic structure determined with ultrasonic scanning and conventional liver-function tests were basally normal in all patients, with a slight increase of liver volume in three cases. No change of biochemical and/or morphological features occurred during follow-up evaluation. The results support the hypothesis that GH and especially IGF-I enhance liver metabolic capacity; conversely, functional liver perfusion is largely independent of their actions. Our data also suggest that octreotide is unable to produce well-structured changes of liver circulation when administered long-term.

Acromegaly↗
PubMed1980

Non-specificity of circulating immune complexes in patients with acute and chronic liver disease.

Circulating immune complexes have been described in viral hepatitis and primary biliary cirrhosis but their significance is unclear. Seventy-three patients with acute and chronic liver diseases were evaluated to determine the specificity of immune complex detection for a given liver disease. Immune complexes were measured by the fluid- and solid-phase Clq-binding assays. They were demonstrated frequently in all patients with liver disease, including those with viral hepatitis, alcoholic cirrhosis, chronic active and persistent hepatitis, drug-induced hepatitis and hepatic metastases. The presence of immune complexes was not specific for a given type of liver disease and did not correlate with hepatic dysfunction. We conclude that the detection of immune complexes is of no apparent diagnostic use in liver disease. Further evaluation of the antigen-antibody composition would be required to determine any pathogenic significance of the detected circulating immune complexes.

Acute Disease↗
PubMedDate not supplied

Glycine modulates hepatic lipid accumulation in alcohol-induced liver injury.

We studied the effect of administering glycine, a non-essential amino acid, on serum and tissue lipids in experimental hepatotoxic Wistar rats. All the rats were fed standard pellet diet. Hepatotoxicity was induced by administering ethanol (7.9 g kg(-1)) for 30 days by intragastric intubation. Control rats were given isocaloric glucose solution. Glycine was subsequently administered at a dose of 0.6 g kg(-1) every day by intragastric intubation for the next 30 days. Average body weight gain at the end of the total experimental period of 60 days was significantly lower in rats supplemented with alcohol, but improved on glycine treatment. Feeding alcohol significantly elevated the levels of cholesterol, phospholipids, free fatty acids and triglycerides in the serum, liver and brain as compared with those of the control rats. Subsequent glycine supplementation to alcohol-fed rats significantly lowered the serum and tissue lipid levels to near those of the control rats. Microscopic examination of alcohol-treated rat liver showed inflammatory cell infiltrates and fatty changes, which were alleviated on treatment with glycine. Alcohol-treated rat brain demonstrated edema, which was significantly lowered on treatment with glycine. In conclusion, this study shows that oral administration of glycine to alcohol-supplemented rats markedly reduced the accumulation of cholesterol, phospholipids, free fatty acids and triglycerides in the circulation, liver and brain, which was associated with a reversal of steatosis in the liver and edema in the brain.

Animals↗
PubMed2003

Deletion of IFN-gamma reduces fumonisin-induced hepatotoxicity in mice via alterations in inflammatory cytokines and apoptotic factors.

Fumonisin B(1) (FB(1)) produces species-specific and organ-specific toxicity, including equine leukoencephalomalacia, porcine pulmonary edema, and hepatic or renal damage in other animals. FB(1) causes inhibition of ceramide synthase, leading to accumulation of free sphingoid bases. We previously reported that such cytokines as tumor necrosis factor-alpha (TNF-alpha) modify FB(1)-induced hepatic apoptosis in male mice. FB(1) also caused induction of interferon-gamma (IFN-gamma) in mouse liver, and, therefore, it was worthwhile to determine the role IFN-gamma plays in FB(1) toxicity. In the current study, male IFN-gamma-knockout (GKO) mice and their wild-type (WT) counterparts, C57BL/6J, were treated subcutaneously (s.c.) with 2.25 mg/kg/day of FB(1) for 5 days and sampled 1 day after the last injection. The levels of circulating liver enzymes were increased in WT animals but considerably less in GKO mice. Reduced hepatotoxicity in GKO mice was evident by histologic evaluation and enumeration of apoptotic cells. The induction of TNF-alpha and interleukin-12 (IL-12) p40 by FB(1) in liver was less in GKO mice compared with WT animals. The GKO mice also had a reduced accumulation of liver sphinganine than did WT mice after FB(1) treatment. Results suggested the implication of IFN-gamma in FB(1)-induced hepatotoxicity, which can be explained by a lack of TNF-alpha and IL-12 amplification in the liver of the GKO mice. In addition, the GKO mice had altered expression of various apoptotic and antiapoptotic factors in liver. These changes were accompanied by a greater number of proliferating cells in the liver of GKO mice after FB(1) treatment, which may also contribute to the reduced hepatotoxicity of FB(1) in GKO mice. Whereas the GKO mice show reduced sensitivity to FB(1) and FB(1) treatment elevates IFN-gamma expression, decreased hepatotoxicity to FB(1) could result from alterations in sphingolipid metabolism in the GKO strain.

Animals↗
PubMed1986

Redistribution of renal blood flow in patients with liver cirrhosis. The role of renal PGE2.

Cirrhotic patients frequently show a decrease in renal blood flow and redistribution of the flow from the outer cortex to the juxtamedullary cortex. The cause of the maintenance of juxtamedullary perfusion is not presently known. Prostaglandin E2 (PGE2) has its vasodilating effect on medullary and juxtamedullary vessels where it is synthesized. Therefore, its increased production, frequently shown in cirrhotics, could be responsible for the relative preservation of juxtamedullary blood flow. To verify this hypothesis we examined 13 cirrhotic patients. In these patients we determined mean renal blood flow (MRBF), blood flow in the 1st compartment (ICBF) and in the 2nd compartment (IICBF) with the 133-Xenon washout technique and PGE2 plasma levels in the renal veins (PGE2V). MRBF and ICBF were significantly reduced as compared to control subjects (P less than 0.01); IICBF resulted unaltered. Significant correlation was found between IICBF and PGE2V (P less than 0.01). Our data confirm the decrease in renal blood flow and the redistribution of intrarenal blood flow in cirrhotic patients. The maintenance of IICBF is likely to be a consequence of PGE2 renal production.

Adult↗
PubMed1994

Octreotide prevents postprandial splanchnic hyperemia in patients with portal hypertension.

An increase in splanchnic blood flow is a physiological response to food intake. In patients with cirrhosis whose hepatic vascular resistance is already high, this increase in flow leads to marked increases in portal pressure. This study investigates whether octreotide prevents the increases in hepatic flow and portal pressure that follow the ingestion of a meal in patients with cirrhosis. Twenty-two patients with cirrhosis and portal hypertension were randomized to receive a mixed liquid meal (520 kcal) plus a single subcutaneous injection of either placebo or octreotide (200 micrograms). In the placebo group the ingestion of a meal was followed by an increase in the hepatic venous pressure gradient (+ 19.4 +/- 4.3%, p < 0.01) and hepatic blood flow (+ 38.2 +/- 14.6%, p < 0.05) at 30 min. In contrast, in the octreotide group eating caused no significant change in the hepatic venous pressure gradient (-2.8 +/- 3.6%, NS), while hepatic flow was decreased (-6.08 +/- 5.4%, p < 0.05). Octreotide blunted the postprandial increase in serum insulin and glucagon levels observed in the placebo group. In conclusion, in patients with cirrhosis and portal hypertension, octreotide prevents the postprandial increase in hepatic blood flow, and consequently also in portal pressure. These findings suggest that this drug could play a role in the long-term management of portal hypertension.

Blood Glucose↗
PubMed2001

Noninvasive grading of the severity of portal hypertension in cirrhotic patients by echo-color-Doppler.

The possibility of estimating portal hypertension combining splenic Doppler pulsatility index (PI), which has been shown strictly to be related to portal resistance, and portal blood flow (PBF) was evaluated. Hepatic venous pressure gradient, and splanchnic Doppler parameters were measured in 40 cirrhotic patients. A formula to assess the severity of portal hypertension from Doppler parameters was calculated in a training group of 19 patients, and then this formula was tested to prospectively predict the degree of portal pressure in 21 further patients. In the training group, the regression of portal resistance over splenic PI was calculated and individual values of estimated portal resistance were obtained for every patient of the test group. From them and from observed values of PBF, an estimated value of portal pressure was calculated. The following formula was obtained [(0.066*splenic PI -0.044)*PBF]. In the second group, predicted and observed portal pressure were well correlated (r = 0.71, p = .0003). A good accuracy for the prediction of mild or severe portal hypertension was obtained.

Adult↗
PubMed2001

Randomized comparison of long-term losartan versus propranolol in lowering portal pressure in cirrhosis.

BACKGROUND & AIMS: It has been suggested that losartan, an angiotensin II (A-II) type 1 receptor blocker, may have a pronounced portal pressure reducing effect, far greater than that of propranolol. This randomized controlled trial compared the hemodynamic and renal effects of continued 6-week administration of losartan (n = 25) vs. propranolol (n = 15) in portal hypertensive patients with cirrhosis treated endoscopically after a variceal bleeding episode. METHODS: Hepatic venous pressure gradient (HVPG), systemic hemodynamics, renal function, and vasoactive factors were measured before and at 6 weeks of treatment. RESULTS: Losartan did not reduce HVPG (-2% +/- 12%, NS) but significantly decreased mean arterial pressure (MAP, -8% +/- 10%, P = 0.001). On the contrary, propranolol significantly reduced HVPG (-10% +/- 11%, P = 0.003) and cardiac output (-16% +/- 12%, P = 0.001) but did not modify MAP (2.5% +/- 10%, NS). Losartan increased A-II levels, reduced aldosterone, and decreased glomerular filtration rate (GFR) in Child B patients. Propranolol did not modify renal function. Adverse events related to therapy were mild and similar in both groups. CONCLUSIONS: Unlike propranolol, long-term losartan administration does not significantly reduce HVPG in patients with cirrhosis treated after a variceal bleeding episode, and it caused hypotension and reduced GFR in patients with moderate liver failure. Therefore, losartan is not an alternative to propranolol in preventing variceal rebleeding.

Adult↗
PubMed2002

Randomized comparison of long-term carvedilol and propranolol administration in the treatment of portal hypertension in cirrhosis.

Short-term carvedilol administration is more powerful than propranolol in decreasing hepatic venous pressure gradient (HVPG) in cirrhotic patients, but induces arterial hypotension that may prevent its long-term use in portal hypertensive patients. This study compared the HVPG reduction and safety of long-term carvedilol and propranolol. Fifty-one cirrhotic patients were randomly assigned to receive carvedilol (n = 26) and propranolol (n = 25). Hemodynamic measurements and renal function were assessed at baseline and after 11.1 +/- 4.1 weeks. Carvedilol caused a greater decrease in HVPG than popranolol (-19 +/- 2% vs. -12 +/- 2%; P <.001). The proportion of patients achieving an HVPG reduction >/=20% or </=12 mm Hg was greater after carvedilol (54% vs. 23%; P <.05). Carvedilol, but not propranolol caused a significant decrease in mean arterial pressure (MAP) (-11 +/- 1% vs. -5 +/- 3%; P =.05) and a significant increase in plasma volume (PV) and body weight (11 +/- 5% and 2 +/- 1%, respectively; P <.05). Glomerular filtration rate (GFR) was unchanged with either drug, but the dose of diuretics was increased more frequently after carvedilol (27% vs. 8%; P =.07). Adverse events requiring discontinuation of treatment occurred in 2 patients receiving carvedilol and in 3 receiving propranolol. In conclusion, carvedilol has a greater portal hypotensive effect than propranolol in patients with cirrhosis. However, its clinical applicability may be limited by its systemic hypotensive effects. Further trials are needed to confirm the therapeutic potential of carvedilol.

Antihypertensive Agents↗