thromboxane-a2 and Liver-Diseases

A severe case of preeclampsia with Hellp Syndrome is reported. Clinical findings, laboratory abnormalities and pathogenesis, were discussed. We concluded that severe preeclampsia and Hellp Syndrome are not different diseases, but the natural course of preeclampsia per se.

Topics: Adult; Anemia, Hemolytic; Anticonvulsants; Antihypertensive Agents; Cesarean Section; Combined Modality Therapy; Epoprostenol; Female; Humans; Incidence; Liver Diseases; Pre-Eclampsia; Pregnancy; Syndrome; Thrombocytopenia; Thromboxane A2; Vasoconstriction

Systemic inflammation and severe fibrosis can reduce serum zinc levels, while zinc supplementation is reported to improve the prognosis of patients with chronic liver disease (CLD).. We aimed to investigate the clinical application of serum zinc in patients with CLD and the anti-infective mechanism of zinc supplementation.. Based on the serum zinc level, 149 CLD patients were divided into 3 groups and their clinical parameters were compared. In in-vitro experiments, microbial isolates derived from patients were used to stimulate human liver non-parenchymal cells, and the zinc sulfate solution was added in certain experiments. The effect of zinc was compared by LDH and thromboxane A. Compared with other groups, patients with low serum zinc levels had significantly higher C-reactive protein (CRP), total bilirubin, INR, creatinine, and MELD scores, while albumin and GOT levels were reduced. Only CRP and albumin were significantly correlated with serum zinc in both low and normal-zinc groups. Bacterial isolates significantly increased LDH levels in Kupffer cells (KCs) and stellate cells but had no effect on sinusoidal endothelial cells, whereas zinc pretreatment protected KCs but not stellate cells. Thromboxane A. Serum zinc levels can be used to estimate infection and liver fibrosis in CLD patients. As a new antibacterial weapon, zinc supplementation acts on KCs through Myd88-MAPK related pathways.

Topics: Adult; Aged; Chronic Disease; Female; Gene Expression Regulation; Hepatic Stellate Cells; Humans; Kupffer Cells; Liver Cirrhosis; Liver Diseases; Male; Middle Aged; Thromboxane A2; Zinc; Zinc Sulfate

This study sought to determine whether in vivo inhibition of thromboxane A2 (TXA2) action contribute to attenuate hepatic damage after bile duct ligation (BDL). Male Wistar rats were assigned to sham operation or BDL. At the time of operation, infusion pump with saline, ozagrel natrium (TXA2 synthase inhibitor), or SQ29548 (TXA2 receptor antagonists) was implanted in the abdominal cavity. Plasma alanine aminotransferase, aspartate aminotransferase, hyaluronic acid, and total bilirubin levels were measured at 4 days after the operation. The levels of plasma TXB2, a stable metabolite of TXA2, were significantly increased after BDL. Gene expression of TXA2 synthase was also significantly upregulated in the liver. Nonetheless, either an inhibition of TXA2 synthesis by ozagrel natrium or a blockade of TXA2 receptor by SQ29548 has no effect in every measured parameter related to hepatic function. These results indicated that despite a highly increased production in the liver, TXA2 is not directly related to the hepatic injury in BDL rats.

Topics: Alanine Transaminase; Animals; Bilirubin; Bridged Bicyclo Compounds, Heterocyclic; Enzyme Inhibitors; Fatty Acids, Unsaturated; Gene Expression Regulation, Enzymologic; Hyaluronic Acid; Hydrazines; Liver; Liver Diseases; Male; Methacrylates; Rats; Rats, Wistar; Receptors, Thromboxane A2, Prostaglandin H2; Thromboxane A2; Thromboxane B2; Thromboxane-A Synthase; Time Factors

Lipid mediators, thromboxane A2 (TxA2) and platelet-activating factor (PAF), are potent vasoconstrictors, and have been implicated as mediators of liver diseases, such as ischemic-reperfusion injury. We determined the effects of a TxA2 analogue (U-46619) and PAF on the vascular resistance distribution and liver weight (wt) in isolated guinea pig livers perfused with blood via the portal vein. The sinusoidal pressure was measured by the double occlusion pressure (P(do)), and was used to determine the pre- (R(pre)) and post-sinusoidal (R(post)) resistances. U-46619 and PAF concentration-dependently increased the hepatic total vascular resistance (R(t)). The minimum concentration at which significant vasoconstriction occurs was 0.001 microM for PAF and 0.1 microM for U-46619. Moreover, the concentration of U-46619 required to increase R(t) to the same magnitude is 100 times higher than PAF. Thus, the responsiveness to PAF was greater than that to U-46619. Both agents increased predominantly R(pre) over R(post). U-46619 caused a sustained liver weight loss. In contrast, PAF also caused liver weight loss at lower concentrations, but it produced liver weight gain at higher concentrations (2.5 +/- 0.3 per 10g liver weight at 1 microM PAF), which was caused by substantial post-sinusoidal constriction and increased P(do). In conclusion, both TxA2 and PAF contract predominantly the pre-sinusoidal veins. TxA2 causes liver weight loss, while PAF at high concentrations increases liver weight due to substantial post-sinusoidal constriction in isolated guinea pig livers.

Topics: 15-Hydroxy-11 alpha,9 alpha-(epoxymethano)prosta-5,13-dienoic Acid; Animals; Bile; Capillary Permeability; Guinea Pigs; In Vitro Techniques; Infusion Pumps; Liver; Liver Circulation; Liver Diseases; Male; Organ Size; Platelet Activating Factor; Portal Vein; Reperfusion Injury; Thromboxane A2; Vascular Resistance; Vasoconstriction; Vasoconstrictor Agents

The plasma levels of thromboxane B2 (TxB2) and 6-keto-prostaglandin F1alpha (6-KF) in the peripheral and portal blood increase after an extensive hepatectomy, and even more so in cases with complications. In this cell biological study, we estimated the prostanoids in the portal system to clarify which organ produces them, while also evaluating the effect of a splenectomy in conjunction with an extensive hepatectomy. Our results showed that the level of TxB2 in the splenic vein was significantly higher than that in the mesenteric vein. Furthermore, the TxA2 produced by splenic macrophages after an extensive hepatectomy was significantly more than after a sham operation. We also observed the hepatocyte damage to be less in the group that underwent an 84% hepatectomy and splenectomy than in the group that underwent the same hepatectomy without a splenectomy. It therefore appears important both to suppress the splenic macrophages from producing TxA2 and to prevent remnant hepatic dysfunction after an extensive hepatectomy.

Topics: 6-Ketoprostaglandin F1 alpha; Animals; Cell Survival; Dogs; Female; Hepatectomy; Liver Diseases; Macrophages; Male; Portal System; Spleen; Splenectomy; Thromboxane A2; Thromboxane B2

The effects of endothelin 1 (ET-1) on hemodynamics and acute liver damage were studied using perfused livers of rats treated with D-galactosamine. In control liver perfused in situ with constant pressure, infusion of ET-1 into the portal vein at a concentration of 0.1 nmol/L decreased the flow rate without a significant leakage of lactate dehydrogenase (LDH) or aspartate transaminase (AST) into the effluent. In contrast, in similarly perfused liver 24 hours after treatment with D-galactosamine (800 mg/kg intraperitoneally), ET-1 caused rapid and remarkable increases in the leakage of LDH and AST from the liver accompanied by the reduction of perfusion flow to the extent similar to that observed in control livers. In addition, ET-1 decreased oxygen uptake and bile secretion in galactosamine-treated livers. The potentiating effects of ET-1 on enzyme leakage were also observed under constant flow conditions. Moreover, infusion of the thromboxane A2 analogue at a concentration of 10 nmol/L decreased the flow rate markedly, yet the rapid increases in enzyme leakage were not observed. Infusion of ET-3 induced the responses of flow reduction and the potentiation of rapid enzyme leakage similar to those obtained with ET-1. Neither the endothelin A-receptor antagonist BQ485 nor the endothelin B-receptor antagonist BQ788 could inhibit the acute liver damage caused by ET-1; instead they exaggerated its effects. The combination of both antagonists together, however, almost completely suppressed the flow reduction and the potentiation of enzyme leakage caused by ET-1. These results indicate that ET-1 is capable of aggravating acute liver damage not merely through reduction of the flow rate but through direct action on liver cells. They also suggest that both the endothelin A and endothelin B receptors are involved in this action of ET-1.

Topics: Acute Disease; Animals; Aspartate Aminotransferases; Chemical and Drug Induced Liver Injury; Dose-Response Relationship, Drug; Endothelin Receptor Antagonists; Endothelin-1; Endothelin-3; Galactosamine; Hemodynamics; L-Lactate Dehydrogenase; Liver; Liver Circulation; Liver Diseases; Male; Perfusion; Rats; Rats, Sprague-Dawley; Thromboxane A2

To assess the role of altered renal and systemic production of thromboxane A2 and prostacyclin in the hepatorenal syndrome, urinary excretion of their major renal and extrarenal metabolites was measured in patients with compensated and decompensated liver disease, chronic renal failure, and hepatorenal syndrome. Urinary excretion rates of all prostanoids (renal and extrarenal) were increased in subjects with liver disease compared with normal controls. Moreover, they were considerably higher in subjects with severe hepatic decompensation but good renal function compared with those with hepatorenal syndrome. In contrast, the excretion rate of all metabolites was reduced in patients with chronic renal failure. The excretion rate of all metabolites was markedly elevated during the early stages of hepatorenal syndrome and decreased in parallel with creatinine clearance. When corrected for creatinine clearance, there was a strong correlation between prostanoid excretion and serum bilirubin in subjects with liver disease; there was no difference, however, in the excretion of renal and extrarenal prostanoids between hepatorenal syndrome and severe hepatic decompensation. It is concluded that hepatic decompensation is associated with a progressive increase in prostanoid excretion but that changes in production of prostacyclin or thromboxane A2 are unlikely to be major factors in the pathogenesis of the hepatorenal syndrome.

Topics: Adult; Aged; Ascites; Bilirubin; Creatinine; Dinoprost; Epoprostenol; Female; Hepatorenal Syndrome; Humans; Kidney; Kidney Failure, Chronic; Liver Cirrhosis; Liver Diseases; Male; Middle Aged; Thromboxane A2; Thromboxane B2

Interleukin-2 (IL-2) produces toxicity characterized by generalized edema within 24 hours. This study tests whether the rate of IL-2 administration modulates the onset of edema and examines thromboxane (Tx) and neutrophils as possible mediators of this event. Recombinant human IL-2, 10(5) U (n = 7), 10(6) U (n = 9), or vehicle (n = 8) were given to anesthetized rats intravenously during a period of 1 hour. At 6 hours edema, as measured by increase in wet to dry weight (w/d) ratio, was present in the heart, liver, and kidney, with 10(5) U IL-2 and in the lung, heart, liver and kidney, with 10(6) U IL-2, relative to values with vehicle-infused controls (all p less than 0.05). With a 1-hour infusion of 10(6) U IL-2, there was an increase in plasma thromboxane (Tx)B2 level to 1290 +/- 245 pg/mL, higher than 481 +/- 93 pg/mL in control rats (p less than 0.05); lung polymorphonuclear leukocyte (PMN) sequestration of 53 +/- 7 PMN/10 higher-power fields (HPF) relative to 23 +/- 2 PMN/10 HPF in controls (p less than 0.05); and increased bronchoalveolar lavage (BAL) fluid protein concentration of 1970 +/- 210 micrograms/mL relative to 460 micrograms/mL in controls (p less than 0.05). When 10(6) U IL-2 was given as a 1-minute intravenous bolus (n = 9), edema was not demonstrated, plasma TxB2 levels were similar to controls, there was no leukosequestration, and BAL protein levels were normal. These data indicate that a constant infusion but not the rapid bolus administration of IL-2 produces in rats multiple-system organ edema, increased plasma TxB2, sequestration of PMNs, and microvascular permeability. These findings may explain the early toxicity seen in patients given high-dose IL-2 in cancer treatment.

Topics: 6-Ketoprostaglandin F1 alpha; Animals; Bronchoalveolar Lavage Fluid; Edema; Heart Diseases; Infusions, Intravenous; Injections, Intravenous; Interleukin-2; Kidney Diseases; Liver Diseases; Male; Neutrophils; Pulmonary Edema; Rats; Rats, Inbred Strains; Recombinant Proteins; Thromboxane A2; Thromboxane B2

This paper reports on investigations of the formation of PGI2 and TXA2 using their stabile products 6-keto-PGF1 alpha and TXB2 (RIA) in liver biopsy specimens of 46 patients suffering from fatty liver (n = 19), chronic hepatitis B (n = 11), liver cirrhosis (n = 13), and miscellaneous diseases (n = 3). The measured formation rates in chronic liver disease were evaluated in comparison to a reference group (n = 19) consisting of minimal liver lesions. The 6-keto-PGF1 alpha formation correlating to the degree of the portal inflammation in the liver (morphometric evaluation). The same trend existed in relation to the intralobular inflammation. The results presented suggest in respect of analogous data in animal experiments that PGI2 is predominantly generated in mesenchymal cells of the liver and, presumably influences the course of liver diseases.

Topics: 6-Ketoprostaglandin F1 alpha; Chronic Disease; Epoprostenol; Female; Humans; Liver; Liver Diseases; Male; Thromboxane A2; Thromboxane B2

Macrophages isolated from liver granulomas of mice infected with Schistosoma mansoni for 8 or 20 wk synthesize predominantly thromboxane A2 with smaller amounts of the PGE2 and PGI2. There is no physiologic production of leukotrienes, as determined by RIA and HPLC. Thromboxane A2 is the predominant arachidonic acid metabolite whether the cells are stimulated by a phagocytic stimuli such as zymosan or the exogenous substrates arachidonic acid and PGH2. These data indicate that the predominant arachidonate enzymatic activity in these cells is thromboxane synthase.

Topics: 12-Hydroxy-5,8,10,14-eicosatetraenoic Acid; Acute Disease; Animals; Arachidonic Acid; Arachidonic Acids; Chronic Disease; Granuloma; Hydroxyeicosatetraenoic Acids; Liver Diseases; Macrophage Activation; Macrophages; Mice; Prostaglandin Endoperoxides, Synthetic; Prostaglandin H2; Prostaglandins H; Schistosomiasis mansoni; SRS-A; Thromboxane A2; Thromboxane-A Synthase