Biomedical subjects

D Sacerdoti

Publications and source records attributed to D Sacerdoti.

At least 19 recordsLinked to original sources

PubMed2005

Heme oxygenase-1 transduction in endothelial cells causes downregulation of monocyte chemoattractant protein-1 and of genes involved in inflammation and growth.

Heme oxygenase (HO-1) has been implicated as an anti-inflammatory gene. HO-1 overexpression, transiently and chronically, affects heme protein expression, attenuates TNF-mediated cell death, and decreases adhesion molecules. We assessed the effect of oxidant-mediated agents such as glucose and heme on 8-epi-isoprostane PGF2alpha (8-epi-PGF2alpha) and monocyte chemoattractant protein-1 (MCP-1). Glucose and heme increased both 8-epi-PGF2alpha and MCP-1. Overexpression of HO-1 decreased both 8-epi-PGF2alpha and MCP-1. To identify target genes involved in HO-1-mediated regulation of inflammation, a serial analysis of gene expression mRNA profile was performed in endothelial cells (EC) overexpressing the human HO-1 gene by transduction of a retrovirus carrying the HO-1 gene. Gene arrays (differential displays among 2400 genes) were used to identify known and novel differentially expressed genes. The levels of expression for several genes were confirmed by real time PCR in cells overexpressing the HO-1 gene. In HO-1 overexpressing cells, VEGF and the prostaglandin transporter were greatly increased while MCP-1 levels were decreased by 2.5-fold. The data from this study are relevant to understanding the mechanisms underlying the pathophysiological effects of HO-1 deficiency on endothelial cell injury and inflammation.

Cell Cycle↗

PubMed2005

Disagreement between acute and chronic haemodynamic effects of nadolol in cirrhosis: a pathophysiological interpretation.

BACKGROUND: The acute effects of beta-blockers may be different from chronic; mechanisms underlying this difference are poorly elucidated. AIM: To assess portal pressure and its pathophysiological determinants after acute and chronic administration of nadolol. METHODS: In 24 patients with cirrhosis and portal hypertension hepatic venous pressure gradient, portal blood flow and resistance to portal blood flow were measured before, 60-90 min after acute administration of nadolol, and after 1 month. Patients were good-responders if hepatic venous pressure gradient was < or =12 mmHg, or decreased by at least 20%. RESULTS: Eleven and 13 patients were good- and poor-responders to acute administration, respectively. Acute poor-responders showed a lower decrease in portal blood flow (P = 0.04) and a less evident decrease in mean arterial pressure (P < 0.001). Eleven and 13 patients were good- and poor-responders to chronic administration, respectively. Chronic poor-responders showed a larger increase in resistance to portal blood flow compared with good-responders (P = 0.01). Disagreement between acute and chronic effects was seen in 12 patients: six were acute good-responders chronic poor-responders and six were acute poor-responders chronic good-responders. Acute good-responders chronic poor-responders patients had the smallest decreases in portal blood flow and in mean arterial pressure after acute administration, while acute poor-responders chronic good-responders showed the largest (P = 0.05 and 0.01). CONCLUSIONS: Disagreement between acute and chronic effects of nadolol on hepatic venous pressure gradient is common. The mechanism responsible is complex, the acute effect being mainly modulated by arterial hypotension and the chronic effect by changes in portal resistance.

Acute Disease↗

PubMed2005

Haeme oxygenase mediates hyporeactivity to phenylephrine in the mesenteric vessels of cirrhotic rats with ascites.

BACKGROUND AND AIMS: Haeme oxygenase could play a role in the pathogenesis of arterial vasodilation in cirrhosis. The aim of this study was to verify the role of haeme oxygenase in the hyporesponsiveness to phenylephrine of small mesenteric arteries in rats with CCl(4) induced cirrhosis, with and without ascites. METHODS: Pressurised small resistance mesenteric arteries were challenged with increasing doses of phenylephrine. Dose-response curves were evaluated under basal conditions, after inhibition of haeme oxygenase with chromium-mesoporphyrin, after inhibition of nitric oxide synthase (NOS) with N(G)-nitro-L-arginine-methyl-ester (L-NAME), and then after inhibition of both NOS and haeme oxygenase. Haeme oxygenase protein expression was also analysed. RESULTS: Twenty six control rats and 35 rats with cirrhosis (17 with and 18 without ascites) were studied. Response to phenylephrine was lower in non-ascitic and ascitic cirrhosis than in controls. Chromium-mesoporphyrin increased the response to phenylephrine only in ascitic cirrhosis (p<0.001). L-NAME increased the response to phenylephrine in controls (p<0.001) and in ascitic and non-ascitic cirrhosis (p = 0.002, p<0.001, respectively) but the final response in non-ascitic cirrhosis was similar to that of control rats while it remained impaired in ascitic cirrhosis. Addition of chromium-mesoporphyrin to L-NAME improved the response to phenylephrine in ascitic cirrhosis (p<0.01), with final values not different from those of the other two groups. Protein expression of the inducible isoform of haeme oxygenase was increased in the mesenteric vessels of cirrhotic rats. CONCLUSION: Haeme oxygenase mediates hyporeactivity to phenylephrine in the mesenteric vessels of experimental cirrhosis with ascites. NOS plays a major role only in the first stage of the disease.

Animals↗

PubMed2002

Role of spleen enlargement in cirrhosis with portal hypertension.

The possible relationships between splenomegaly and portal hypertension have been analysed in patients with cirrhosis. In this condition, splenomegaly is not only caused by portal congestion, but it is mainly due to tissue hyperplasia and fibrosis. The increase in spleen size is followed by an increase in splenic blood flow, which participates in portal hypertension actively congesting the portal system.

Endothelins↗

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

Gemfibrozil improves insulin sensitivity and flow-mediated vasodilatation in type 2 diabetic patients.

BACKGROUND: Endothelial dysfunction is an early feature of atherosclerosis. The relationship between insulin action and hypertriglyceridaemia on endothelial function is still debated. MATERIALS AND METHODS: This study was designed to determine the effect of a 3 month treatment with Gemfibrozil (GF) on flow-mediated vasodilatation and insulin sensitivity. Ten type 2 diabetic patients were randomised in crossover, double blind fashion, either to GF, 600 mg b.i.d. or placebo, for 12 weeks. Lipid profile, low-density lipoprotein (LDL) distribution and flotation properties, insulin action and flow-mediated vasodilatation (FMD) by brachial artery ultrasound, were assessed. RESULTS: GF decreased serum triglyceride (TG) concentration with an absolute difference of 1.79 +/- 1.28 mmol L-1 (P < 0.0016) between active treatment and placebo, and significantly increased serum high-density lipoprotein (HDL) cholesterol (P = 0.0233). No differences were observed in total, intermediate-density lipoproteins (IDL), LDL cholesterol concentration and LDL peak buoyancy between treatments. GF also improved SI, an index of insulin action (P = 0.005). The FMD was 7 +/- 3% in the baseline condition, 7 +/- 2% during placebo and 14 +/- 3% after GF (P < 0.006). CONCLUSIONS: GF treatment improves both insulin action and flow-mediated vasodilatation in type 2 diabetic patients. The reduction of TG concentration allows the simultaneous correction of two important components of the metabolic syndrome.

Aged↗

PubMed2000

Long-term results of a clinical trial of nadolol with or without isosorbide mononitrate for primary prophylaxis of variceal bleeding in cirrhosis.

It is clearly established that beta-blockers decrease the risk of a first variceal bleeding in cirrhosis. We have recently shown that the addition of isosorbide mononitrate to nadolol decreases the rate of variceal bleeding in patients with cirrhosis and varices, compared with nadolol alone, after a median follow-up of 30 months. It is not established if the long-term treatment with the combination continues to be beneficial. Therefore, we assessed the long-term effect of this combination on first variceal bleeding, complications, and death. One hundred forty-six cirrhotic patients with esophageal varices included in a previously published multicenter, randomized study comparing nadolol (40-160 mg/d) with the combination nadolol plus isosorbide mononitrate (10-20 mg 3 times per day) were followed up for up to 7 years (median follow-up, 55 months). The primary end-point was variceal bleeding of any severity. Twenty-four patients (16 in the nadolol group, and 8 in the combination group) experienced variceal bleeding (log rank test, P =.02). Cumulative risk of bleeding was 29% and 12%, respectively (95% CI for the difference, 1%-23%). Two and 4 patients, respectively, had bleeding from portal hypertensive gastropathy (log rank test, P =.20). Thirty and 25 patients, respectively, died during follow-up (log rank test, P =.13). Twelve and 10 patients, respectively, had de novo occurrence of ascites during follow-up (log rank test, P =.29). In conclusion, nadolol plus isosorbide mononitrate is significantly more effective than nadolol alone in the long-term use. Side effects are few, and no deleterious effects on ascites occurrence or on survival occur after long-term use of this combination.

Adolescent↗

PubMed2000

The hemodynamic response to medical treatment of portal hypertension as a predictor of clinical effectiveness in the primary prophylaxis of variceal bleeding in cirrhosis.

In the prevention of variceal rebleeding, it is already established that hemodynamic response to drug treatment (decrease in hepatic venous pressure gradient [HVPG] to 12 mm Hg or by >20%) is predictive of clinical effectiveness. In primary prophylaxis very few clinical data are available. We assessed the role of the hemodynamic response to beta-blockers or beta-blockers plus nitrates in predicting clinical efficacy of prophylaxis. A total of 49 cirrhotic patients with varices at risk of bleeding, without prior variceal bleeding, were investigated by hepatic vein catheterization before and after 1 to 3 months of chronic treatment with nadolol or nadolol plus isosorbide mononitrate, and were followed during treatment for up to 5 years. A total of 30 patients (61%) were good hemodynamic responders, and among them in 12 (24%) HVPG was </=12 mm Hg during treatment. During treatment 9 patients had variceal bleeding: 7 were poor responders and 2 were good responders. The probability of bleeding at 3 years of follow-up was significantly higher in poor responders (41%) than in good responders (7%; P =.0008). No patient reaching an HVPG of 12 mm Hg or less during treatment had variceal bleeding during follow-up. Cox's regression analysis showed that poor hemodynamic response was the main factor predicting bleeding (beta = 1.91; SE(beta) = 0.80; P =.01). During follow-up 11 patients died of hepatic causes. Survival was related to Child-Pugh class and to initial value of HVPG, according to Cox's analysis. In conclusion, the assessment of hemodynamic response to drugs in terms of HVPG is the best predictor of efficacy of prophylaxis of variceal bleeding in patients treated with beta-blockers or beta-blockers plus nitrates.

Adrenergic beta-Antagonists↗

PubMed2000

Prognostic indicators of risk for first variceal bleeding in cirrhosis: a multicenter study in 711 patients to validate and improve the North Italian Endoscopic Club (NIEC) index.

OBJECTIVE: The best known indicator of risk for first bleeding in patients with cirrhosis without previous bleeding is the index devised by the North Italian Endoscopic Club for the Study and Treatment of Esophageal Varices (NIEC index), which results from the combination of size of esophageal varices, severity of red wale marks, and Child-Pugh class. Its efficiency is far from optimal, and validation studies have reported sensitivities and specificities markedly lower than those reported in the original study. In the present study we analyzed the efficiency of NIEC index in a large series of cirrhotic patients with varices without previous bleeding. In addition, we tried to improve the effectiveness of the index by modifying it, and to validate the modifications in an independent group of patients. METHODS: A total of 627 patients were enrolled and followed until either a variceal bleeding or for a maximum of 2 yr. During this time, 117 experienced a first variceal RESULTS: Using Cox's regression analysis, size of varices, severity of red wale marks, and Child-Pugh score were significant and independent predictors of first bleeding, as already noted in the original report of the NIEC group. However, coefficients and standard errors were markedly different, and the importance of size of esophageal varices in the regression was much larger, whereas that of Child-Pugh score was much lower. According to these data, a revised index was developed (Rev-NIEC). Using receiver operating characteristic (ROC) curve analysis, the revised index showed a larger efficiency, and the area under the curve was significantly larger (0.80 +/- 0.02 vs 0.74 +/- 0.02; p < 0.01). In particular, the curve showed that for a specificity of 75%, the new index had a sensitivity of 72% compared to that of 55% of the NIEC index. Validation in an independent sample of 84 patients showed good agreement between predicted and observed risk for bleeding. Validation with the bootstrap technique also showed adequate stability of the results. CONCLUSIONS: The revised index seems to be superior to the traditional index, and may turn out to be more useful in the selection of patients for different therapeutic procedures and in the stratification of patients in clinical trials.

Aged↗

PubMed2000

Arterioportal fistulas in patients with liver cirrhosis: usefulness of color Doppler US for screening.

PURPOSE: To evaluate the usefulness of routine ultrasonographic (US) evaluation of the hepatic arterial resistive and pulsatility indexes and of the direction of portal venous blood flow for the diagnosis of intrahepatic arterioportal fistulas (APFs) in patients with liver cirrhosis. MATERIALS AND METHODS: In all patients with cirrhosis examined at one center over 4 years, the resistive (RI) and the pulsatility (PI) indexes in the right and left branches of the hepatic artery were evaluated with Doppler US. An APF was suspected when an RI decrease of at least 20% and a PI decrease of at least 30% were present in one hepatic lobe relative to values in the other lobe and portal blood flow in the lobe with the decreased values was reversed. The RI and PI in patients with an APF were compared with those in 75 patients with cirrhosis and without APFs at angiography. RESULTS: Seven patients with an APF were identified. APFs suspected at Doppler US were always confirmed with angiography. The percent differences +/- SD in the RI and the PI between the two intrahepatic branches of the hepatic artery in patients with versus in patients without an APF were as follows: RI, 35% +/- 6 (range, 27%-42%) versus 5% +/- 4 (range, 0%-15%) (P: <.001); PI, 50% +/- 5 (range, 41%-58%) versus 11% +/- 7 (range, 0%-26%) (P: <.001). CONCLUSION: The intrahepatic arterial resistive and pulsatility indexes and the direction of portal blood flow should be evaluated in routine screening for APFs in patients with liver cirrhosis.

Adult↗

PubMed1999

Effect of chronic treatment with nadolol plus isosorbide mononitrate on liver blood flow and liver metabolic activity in cirrhosis.

OBJECTIVE: To assess the long-term effect of the addition of long-acting nitrates to beta-blockers on liver blood flow and liver metabolic activity in patients with cirrhosis and portal hypertension. METHODS: Eleven patients with cirrhosis and portal hypertension were investigated by using hepatic vein catheterization and indocyanine green (ICG) constant infusion on baseline conditions, after 1 month of treatment with nadolol, after 3 months of treatment with nadolol plus isosorbide mononitrate, and (in seven cases) after 1 year of combined treatment. RESULTS: The hepatic venous pressure gradient decreased significantly after nadolol, and more so after addition of isosorbide mononitrate. Hepatic blood flow, and ICG intrinsic hepatic clearance did not change significantly, although few cases showed an increase or decrease in either parameter. A significant correlation was found between changes in ICG intrinsic hepatic clearance and in hepatic venous pressure gradient (r = 0.62, P = 0.04). CONCLUSIONS: Liver blood flow and liver metabolic activity are not consistently affected by addition of isosorbide mononitrate to nadolol. Substantial decreases in portal pressure may be associated with a decrease in ICG intrinsic hepatic clearance.

Adrenergic beta-Antagonists↗

PubMed1999

Portal hypertension: state of the art.

In the last decade, the knowledge of the pathogenesis of portal hypertension has increased dramatically. Indeed, apart from the well-known pathogenetic importance of structural factors, the role of vasoactive factors, which enhance the increase in intrahepatic resistance, has been highlighted. The two pathogenetic factors of portal hypertension are: the increase in portal outflow resistance and an increase in splanchnic blood flow, which worsens and maintains the increased pressure in the portal vein. The increase in portal inflow is part of the hyperdynamic circulatory syndrome, which is a haemodynamic characteristic of cirrhotic patients. In portal hypertensive patients, almost all the known vasoactive systems/substances are activated or increased and the most recent studies have stressed the importance of the endothelial factors, such as endothelins, nitric oxide and prostaglandins. Knowledge of the haemodynamic mechanisms allows a pathogenetic approach to the treatment of portal hypertension, particularly as far as medical therapy is concerned. The main categories of drugs used are: the vasoconstrictors (i.e., vasopressin, glypressin, somatostatin, non-selective beta-blockers), which act by decreasing portal inflow, and the vasodilators (i.e., nitroderivatives), which act mainly by decreasing intrahepatic portal resistance. Moreover, technological developments have introduced new tools for diagnosis, such as echo-colour-Doppler, and therapy, like variceal banding and transjugular intrahepatic porto-systemic shunt.

Hemodynamics↗

PubMed1998

Splenic impedance indices: a useful method to monitor patients after liver transplantation?

Splenic Doppler impedance indices are influenced, in portal hypertensive patients, by the resistance of the portal system. The aim of the study was to verify the usefulness of these indices in evaluating the presence of a pathological increase in portal resistance in patients with complications after liver transplantation. Splenic impedance indices have been evaluated in 46 patients before orthotopic liver transplantation (OLT), and 2 days, 1, 4, 8, and 12 to 18 months after transplantation. The results showed that spleen size slowly decreased after liver transplantation. From a baseline longitudinal diameter value of 18.0+/-3.6 cm (M+/-SD), the decrease was by 0%+/-3%, 8%+/-8%, 13%+/-9%, 15%+/-11%, and 14%+/-11% at 2 days and 1, 4, 8, and 12 to 18 months after liver transplantation. Splenic impedance indices-resistance index = (peak systolic - end diastolic) / peak systolic velocity; pulsatility index = (peak systolic - end diastolic) / mean velocity-which were increased before liver transplantation, showed a rapid decrease to normal values: resistance index: from 0.62+/-0.08 to 0.55+/-0.08 after 2 days, and to 0.49+/-0.09, 0.51+/-0.10, 0.54+/-0.10, 0.55+/-0.11 after 1, 4, 8, 12-18 months; pulsatility index: from 0.96+/-0.21 to 0.82+/-0.17 after 2 days, and to 0.69+/-0.19,0.72+/-0.21, 0.81+/-0.26, 0.84+/-0.26 after 1, 4, 8, and 12 to 18 months. Patients who had a good outcome, without any major complications, showed a clear and steady decrease in splenic impedance indices. On the contrary, patients who had complications affecting portal resistance (e.g., acute rejection, relapse of chronic hepatitis C virus-related hepatitis or cirrhosis, stenosis of portal anasthomosis, portal thrombosis), showed a lack of decrease, or, after an initial decrease, a subsequent re-increase in splenic impedance indices to pathological values. Splenic impedance indices measured in patients with complications were higher than those of patients without complications (P < .0004). Specificity and sensitivity of splenic impedance indices in the evaluation of the presence of complications increasing portal resistance were good. In conclusion, after OLT, splenic impedance indices could be useful aspecific parameters for identifying patients with complications that are able to affect or increase portal resistance.

Adult↗

PubMed1998

Doppler sonography and hepatic vein catheterization in portal hypertension: assessment of agreement in evaluating severity and response to treatment.

BACKGROUND/AIM: The study was designed to assess to what extent portal hemodynamic parameters obtained by duplex Doppler ultrasonography may be substituted for the measurement of hepatic venous pressure gradient in evaluating the severity of portal hypertension and the response to medical treatment with beta-blockers or beta-blockers plus nitrates in patients with cirrhosis and portal hypertension. METHODS: In 39 of these patients hepatic venous pressure gradient was determined by hepatic vein catheterization, and portal blood flow velocity and the congestion index of the portal vein were measured by duplex Doppler ultrasonography. In 19 of these patients the changes in hepatic venous pressure gradient and in Doppler parameters were also assessed after chronic administration of nadolol. In 11 of the 19 patients the changes after chronic administration of nadolol plus isosorbide-5-mononitrate were also measured. RESULTS: In the whole series, no significant correlation was found between hepatic venous pressure gradient and duplex Doppler parameters, but, when the 12 patients with a patent para-umbilical vein were excluded, significant linear correlations were found between hepatic venous pressure gradient and portal blood velocity (r=-0.39; p=0.05) or congestion index (r=0.37; p=0.05). Considering together the changes induced by nadolol and nadolol plus isosorbide-5-mononitrate, no correlation was apparent between changes in duplex Doppler parameters and in hepatic venous pressure gradient. Agreement between hepatic venous pressure gradient and duplex Doppler parameters in defining good and poor responders was insufficient. CONCLUSIONS: These data suggest that portal blood velocity and the congestion index of the portal vein are related to portal hypertension in patients without a patent para-umbilical vein, but are of limited value in discriminating good responders from poor responders to medical treatment for portal hypertension.

Adrenergic beta-Antagonists↗

PubMed1998

Q-T interval prolongation in liver cirrhosis. Reversibility after orthotopic liver transplantation.

The aim of this work was to study the prevalence of Q-T prolongation in patients with liver cirrhosis and the modifications of the Q-T interval after liver transplantation. Q-T interval corrected for heart rate (QTc) and dispersion of Q-T interval were evaluated in 75 cirrhotic patients and in 24 controls by means of a 12-lead electrocardiogram. In addition, 15 patients were evaluated before and after liver transplantation. Forty-five patients (60%) had a prolonged Q-Tc. Compared with controls, both patients with alcoholic and non alcoholic cirrhosis had increased Q-Tc (414 +/- 28 msec1/2, 463 +/- 31 and 444 +/- 32 respectively; p < 0.001 and < 0.001); Q-Tc was significantly higher in alcoholic than in non-alcoholic cirrhosis (p < 0.02). Q-T dispersion was normal in cirrhotics. No correlation was found between Q-Tc interval and severity of the cirrhosis, haemodynamic variables (stroke volume, cardiac output) and s-calcium and potassium concentrations. After transplantation, Q-Tc decreased significantly (415 +/- 26 msec1/2 vs 449 +/- 31; p < 0.0001) returning to the values of the normal subjects, but no modification of the Q-T dispersion was observed. These data show that 1) prolongation of Q-T interval is frequent in cirrhosis, being higher in alcoholic than in non-alcoholic cirrhosis, 2) is not related to the severity of the disease, and 3) is reversible after transplantation.

Aged↗

PubMed1998

Updating prognosis of cirrhosis by Cox's regression model using Child-Pugh score and aminopyrine breath test as time-dependent covariates.

BACKGROUND AND AIMS: The determination of aminopyrine breath test on entry into the study was recently shown to improve the accuracy of prediction of death based on the Child-Pugh classification, but the possible usefulness of serial determinations of both parameters has not been assessed. In the present study, we aimed at evaluating whether serial determinations of aminopyrine breath test and Child-Pugh score improve prognostic accuracy in patients with cirrhosis, compared with determinations obtained only on admission. PATIENTS: In 74 patients with liver cirrhosis aminopyrine breath test and Child-Pugh score were obtained upon entry into the study. Patients were followed with sequential aminopyrine breath tests and assessments of the Child-Pugh score every 4-6 months. A total number of 232 determinations were obtained. During follow-up 45 patients died, on average after 12 months of follow-up. RESULTS: Child-Pugh score improved in the beginning of follow-up, and then remained fairly constant; aminopyrine breath test showed no improvement in the beginning of follow-up, but rather a slowly progressive decline. In patients who died, both the Child-Pugh score and the metabolism of aminopyrine were significantly more impaired in the last year preceding death (p < 0.05). Applying Cox's regression model with time-dependent covariates, Child-Pugh score and aminopyrine breath test were independent significant predictors of survival. The model with time-dependent covariates explained the observed survival much better than the model with time-fixed covariates (chi-sq. explained by regression = 31.45 vs 11.97; d.f. = 2; p = 0.0000001 vs 0.003). CONCLUSIONS: These data suggest that serial determinations of Child-Pugh score and aminopyrine breath test can be used to efficiently update prognosis of cirrhosis.

Aminopyrine↗

PubMed1997

Eicosanoid excretion in hepatic cirrhosis. Predominance of 20-HETE.

The cytochrome P450 system transforms AA to hydroxyeicosatetraenoic acid (HETE) metabolites that are vasoactive and affect transport in several nephron segments. A principal product of this system, 20-HETE, participates in key mechanisms that regulate the renal circulation and extracellular fluid volume. We hypothesized that excess production of 20-HETE, which constricts the renal vasculature, contributes to the renal functional disturbances in patients with hepatic cirrhosis, particularly the depression of renal hemodynamics. The development of a precise and sensitive gas chromatographic/mass spectrometric method makes it possible to measure 20-HETE and the subterminal HETEs (16-,17-,18-, and 19-HETEs) in biological fluids. As 20-HETE was excreted as the glucuronide conjugate, measurement of 20-HETE required treatment of urine with glucuronidase. We measured HETEs in the urine of patients with cirrhosis, and compared these values to those of normal subjects. Urinary excretion rate of 20-HETE was highest in patients with ascites; 12.5+/-3.2 ng/min vs. 5.0+/-1.5 and 1.6+/-0.2 ng/min in cirrhotic patients without ascites and in normal subjects, respectively. Excretion of 16-, 17-, and 18-HETEs was not increased. In patients with cirrhosis, the excretory rate of 20-HETE was several-fold higher than those of prostaglandins and thromboxane, whereas in normal subjects 20-HETE and prostaglandins were excreted at similar rates. Of the eicosanoids, only increased excretion of 20-HETE in subjects with cirrhosis was correlated (r = -0.61; P < 0.01) with reduction of renal plasma flow (RPF).

Adult↗

PubMed1997

Effects of chronic therapy with nadolol on portal hemodynamics and on splanchnic impedance indices using Doppler sonography: comparison between acute and chronic effects.

BACKGROUND/AIMS: Beta-blockers are currently used for chronic therapy of portal hypertension. Duplex Doppler ultrasonography has been proposed for non-invasive evaluation of splanchnic pharmacodynamics, but the chronic effects of beta-blockers on portal hemodynamics and on splanchnic arterial impedance indices have not been analyzed with this method. This was the aim of the study. METHODS: The effects of acute (80 mg p.o.) and chronic (2 months at a dosage sufficient to reduce heart rate by at least 25% in respect of basal values) nadolol administration on portal blood flow velocity and volume, and on splanchnic and renal arterial impedance indices [pulsatility index = (peak systolic velocity-minimum velocity)/mean velocity] were evaluated in patients with cirrhosis. Twenty-eight patients with cirrhosis and portal hypertension were investigated. Nineteen patients received nadolol, and nine received placebo. RESULTS: Placebo caused no significant hemodynamic change. Portal blood flow mean velocity decreased after chronic therapy (11.7 +/- 2.9 cm/s to 9.1 +/- 2.3, p < 0.001). In the 16 patients with acute and chronic evaluation, portal blood flow mean velocity decreased after acute therapy (11.8 +/- 3.0 cm/s to 10.4 +/- 3.0, p < 0.01), and even more so after chronic therapy (to 9.2 +/- 2.4, p < 0.01). No parallel was found between acute and chronic effects. Hepatic, mesenteric and splenic pulsatility indices increased after chronic therapy (1.26 +/- 0.33 to 1.39 +/- 0.28, p < 0.02; 2.04 +/- 0.41 to 2.50 +/- 0.61, p < 0.01; 0.92 +/- 0.22 to 1.18 +/- 0.27, p < 0.001 respectively); renal pulsatility index increased (1.12 +/- 0.20 to 1.40 +/- 0.28, p < 0.001). CONCLUSIONS: Chronic therapy with nadolol decreased portal blood flow velocity and volume, and increased splanchnic and renal impedance indices. Chronic effects of nadolol on portal inflow cannot be predicted from its acute effects. Evaluation of the effect of nadolol on portal blood velocity and volume should be performed after chronic therapy. Duplex Doppler ultrasonography allows venous and arterial splanchnic pharmacodynamics to be studied separately.

Adrenergic beta-Antagonists↗