BACKGROUND: Thromboxane A2 and endothelin-1 are the potent vasoconstrictors affecting pulmonary pathophysiology in response to whole body inflammatin following CPB. Aprotinin, as an antiiflammatory agent, may decrease the release of such vasoactive substance from pulmonary tissues, preventing pulmonary hypertension after cardiopulmonary bypass. MATERIAL AND METHOD: Ten mongrel dogs(Bwt. ac. 20kg) were subjected to cardioupulmonary bypass for 2 hours and postbypass pulmonary vascular resistance(0, 1, 2, 3 hours) were compared with prebypass level. The dogs were divided into 2 groups; control group(n-5) and aprotinin group(n=5). In the aprotinin group, aprotinin was administered as follows; 50,000 KIU/kg mixed in pump priming solution, 50,000 KIU/kg prebypass intravenous infusion over 30 minutes, 10,000 KIU/kg/hour postbypass continuous infusion. Prebypass and postbypass 0, 1, 2, 3 hour pulmonary vascular resistance were measured. At prebypass and postbypass 0, 90, 180 minutes, blood samples were obtained from pulmonary arterial and left atrial catherers for the assay of plasma thromboxane B2 a stable metabolite of thromboxane A2, and endothelin-1 concentrations. RESULT: The ratios of pustbypass over prebypass pulmonary vascular at postbypass 0, 1, 2, 3 hours were 1.28+/-0.20, 1.82+/-0.23, 1.90+/-0.19, 2.14+/-0.18 in control group, 1.58+/-0.18, 1.73+/-0.01, 1.66+/-0.10, 1.50+/-0.08 in aprotinin group ; the ratios gradually increased in control group while decreased or fluctuated after postbypass 1 hour in aprotinin group. There was statistically significant difference between control group and aprotinin group at postbypass 3 hours(P=0.014). Pulmonary arterial plasma concentration of thromboxane B2(pg/ml) at prebypass, postbypass 0, 90, 180 minutes were 346.4+/-61.9, 529.3+/-197.6, 578.3+/-255.8, 493.3+/-171.3 in control group, 323.8+/-118.0, 422.6+/-75.6, 412.3+/-59.9, 394.5+/-154.0 in aprotinin group. Left atrial concentrations were 339.3+/-89.2, 667.0+/-65.7, 731.2+/-192.7, 607.5+/-165.9 in control group, 330.0+/-111.2, 468.4+/-190.3, 425.4+/-193.6, 4.7.3+/-142.8 in aprotinin group. These results showed decrement of pulmonary thromboxane A2 generation in aprotinin group. Pulmonary arterial concentrations of endothelin-1(fmol/ml) at the same time sequence were 7.84+/-0.31, 13.2+/-0.51, 15.0+/-1.22, 16.3+/-1.73 in control group, 7.76+/-0.12, 15.3+/-0.71, 22.6+/-6.62, 14.9+/-1.11 in aprotinin group. Left atrial concentrations were 7.61+/-17.2, 57.1+/-28.4, 18.9+/-18.2, 31.5+/-20.5 in control group, 5.61+/-7.61, 37.0+/-26.2, 28.6+/-21.7, 37.8+/-30.6 in aprotinin group. These results showed that aprotinin had no effect on plasma endothelin-1 concentration after cardiopulmonary bypass. CONCLUSIONS: Administration of aprotinin during cardiopulmonary bypass could attenuate the increase in pulmonary vascular resistance after bypass. Inhibition of pulmonary thromboxane A2 generation was thought to be one of the mechanism of this effect. Aprotinin had no effect on postbypass endothelin-1 concentration.
Animals ; Aprotinin* ; Cardiopulmonary Bypass ; Dogs ; Endothelin-1* ; Endothelins ; Extracorporeal Circulation* ; Hypertension, Pulmonary ; Infusions, Intravenous ; Plasma* ; Thromboxane A2 ; Thromboxane B2* ; Vascular Resistance ; Vasoconstrictor Agents

Cyclosporine A(CsA) induced nephrotoxicity is a common clinical problem in the patients who underwent organ transplantation and subsequent immunosuppressive therapy. The precise pathophysiology of CsA induced nephrotoxicity still remains uncertain though many hypothesized mechanisms were reported. Therefore, no effective strategy is currently available to counter the nephrotoxic effects of CsA while cyclosporine G or cyclosporine microemulsion was tried to reduce the toxic effects. Recently, CsA was reported to induce lipid peroxidation in renal cortical mitochondria, which may cause mitochondrial damage. To examine the hypothesis of lipid peroxidation in the pathogenesis of acute CsA induced nephrotoxicity, antioxidant vitamin E was co-administerated in the CsA induced acute nephrotoxicity. Sprague Dawley male rats weighing from 250 to 400 gm were heminephrectomized 7 days prior to the experiments. The rats were divided into 3 groups and each group consisted of 7 rats. In group I(control group), the rats were given sterilized olive oil intraperitoneally, in group II(CsA group), CsA 50 mg/kg of body weight/day intraperitoneally, and in group III(CsA with vitamin E), CsA 50 mg/kg of body weight/day intraperitoneally with vitamin E 10 mg/kg of body weight/day intramuscularly for 7 days respectively. From the 6th day, all experimental animals were placed in a metabolic cage collecting urine for the measurement of 24-hours urine thromboxane B2, the metabolite of thromboxane A2. On the 7th day, at the sacrifice of the experimental animals, blood samplings for the measurement of blood CsA level and serum creatinine and left nephrectomy for morphological study were performed. Comparison of mean serum creatinine levels between 2 study groups revealed 171.7+/-164.2 micro Mol/L in group II and 53.4+/-13.9 micro Mol/L in group III(p<0.05). Mean 24-hour urine thromboxane B2 levels were 39.0+/-6.9 ng/24 hours in group I, 74.8+/-22.6 ng/24 hours in group II, and 34.5+/-8.0 ng/24 hours in group III. Urine thromboxane B2 was significantly(p=.0026) lower in group III. The differences of morphological changes in group II and III can be summarized as a diminution of PAS(+) granules under the light microscope and a diminution of the numbers of secondary lysosomes in the proximal tubular epithelial cell under the electron microscope. In conclusion, this animal study provides an evidence that CsA-induced acute nephrotoxicity is related with lipid peroxidation and the antioxidant, vitamin E was considered to ameliorate CsA-induced acute nephrotoxicity in rats.
Animals ; Creatinine ; Cyclosporine* ; Epithelial Cells ; Humans ; Lipid Peroxidation ; Lysosomes ; Male ; Mitochondria ; Nephrectomy ; Olea ; Olive Oil ; Organ Transplantation ; Rats* ; Thromboxane A2 ; Thromboxane B2 ; Transplants ; Vitamin E* ; Vitamins*

In order to find out the relationship between arachidonic acid(AA) metabolites and the development of vasospasm following a subarachnoid hemorrhage(SAH), we evaluated the cerebrospinal fluid(CSF) levels of the two main AA metabolites, prostacyclin(PGI2) and thromboxane A2(TXAZ) by measuring their stable degredation products 6-keto-prostaglandin F1alpha(PGF1) and thromboxane B2(TXB2) using radioimmunoassay methods in 32 patients after an aneurysmal rupture and in 11 patients without an aneurysmal rupture as a control group. We compared the data between aneurysmal ruptured patients and control group patients. We also divided the data of the aneurysmal ruptured patients into 3 groups checking them between 1-4, 5-11, and 12-28 days after the SAH, and compared the data among the groups, then the data was also compared between non-vasospasm and clinical or severe angiographic vasospasm groups of patients. The results showed that the AA metabolism was enhanced after the SAH, The TXB2 increased the greatest amount in 1-4 days after the SAH and significantly decreased statistically 12 days after the SAH(p<0.002). This study also showed that the TXB2 level was significantly higher statistically in 1 to 4 days in the clinical or angiogrophically severe vasospasm group than in the non-vasospasm group of patients(p<0.032). PGF1 did not show any statistically significant changes according to the number of SAH days or a difference between the vasospasm and non-vasospasm groups. This result suggests if the AA metabolites are involved in the pathogenesis of cerebral vasospasm, and the lumbar CSF levels of AA metabolites in aneurysmal patients reflect the arterial synthesis of PGI2 and platelet origin of TXA2, the elevation of TXA2 or other vasoconstrictor prostaglandins is more likely to play a major role in the pathogenesis of vasospasm than PGI2 deficiency. The measurements of the CSF TXB2 in 1 to 4 days after a SAH may have an expectant value in the development of clinical or severe angiographic vasospasm(exclude the accompanying intraventricular hemorrhage patients).
Aneurysm* ; Arachidonic Acid ; Blood Platelets ; Cerebrospinal Fluid* ; Epoprostenol ; Hemorrhage ; Humans ; Metabolism ; Prostaglandins I ; Radioimmunoassay ; Rupture ; Subarachnoid Hemorrhage* ; Thromboxane A2 ; Thromboxane B2* ; Vasospasm, Intracranial

OBJECTIVETo investigate the dynamic changes of plasma levels of prostacycline (PGI2) and thromboxane A2 (TXA2) and their relationship with the severity of hepatic injury in rats with nonalcoholic fatty liver disease (NAFLD).

METHODSWe established a NAFLD model, with a fat-rich diet consisting of 10% lard oil + 2% cholesterol, which was given to Sprague-Dawley rats (n=48) for a period of 8, 12, 16 and 24 weeks. The other rats were fed standard diets and were used as normal controls (n=24). At sacrifice, liver pathology scores were evaluated and plasma levels of PGI2, its stable metabolic product 6-keto-PGF1 alpha and TXA2, and TXB2 were determined by radioimmunoassay.

RESULTSSimple fatty livers were observed in the model group at 8 weeks. From 12 weeks to 24 weeks, the livers gradually progressed from simple steatohepatitis to liver fibrosis. Plasma levels of TXB2 in the model group increased higher than in the control group after 8 weeks [(52.4+/-3.15) ng/L vs (41.1+/-1.45) ng/L] and continued to increase over time, with the highest levels at 24 weeks [(117.7+/-7.47) ng/L]. A strong positive correlation (r=0.537) was seen between plasma TXB2 levels and the severity of liver injury. Plasma 6-keto-PGF1 alpha concentrations decreased in the model group in comparison with the control group after 8 weeks [(31.1+/-1.62) ng/L vs (36.5+/-1.68) ng/L] and continued to decrease over time, with the lowest concentrations at 24 weeks [(3.4+/-2.43) ng/L t=3.77]. A negative correlation was shown between the 6-keto-PGF1 alpha level and the severity of the liver injury.

CONCLUSIONA rat model of NAFLD was established successfully by feeding a fat-rich diet for 24 weeks. In this model, the imbalance of plasma PGI2 and TXA2 levels (increased TXB2 and decreased 6-keto-PGF1 alpha levels) may play a role in the pathogenesis of experimental NAFLD.

6-Ketoprostaglandin F1 alpha ; blood ; Animals ; Epoprostenol ; blood ; Fatty Liver ; blood ; Liver ; pathology ; Male ; Rats ; Rats, Sprague-Dawley ; Thromboxane A2 ; blood ; Thromboxane B2 ; blood

This study was designed to investigate inhibitory effects and possible mechanisms of snake venom tripeptide (pENW) on platelet adhesion in order to promote the development of a novel anti-platelet therapy. To study the inhibitory effects of pENW on platelet adhesion, washed platelets pre-incubated with pENW (116.5-466.2 μmol x L(-1)) were used to test the ability of platelet adhesion to fibrinogen. Effect of pENW on fibrin clot retraction was also tested. Effect of pENW on platelets viability was tested by MTT assay. Effect of pENW on reactive-oxygen species (ROS) levels of platelet was studied by flow cytometry assay. Calcium mobilization in Fura-2/AM-loaded platelets was monitored with a spectrofluorimeter. Cyclic guanosine monophosphate (cGMP) and cyclic adenosine monophosphate (cAMP), thromboxane A2 (determined as its metabolite thromboxane B2) were measured using enzyme immunoassay kits. Akt, ERK and p38 phosphorylation were tested by Western blot. The results showed that pENW inhibited platelet adhesion and fibrin clot retraction in a concentration-dependent manner without cytotoxicity. Intracellular cGMP and cAMP in both resting and thrombin-activated platelets were increased by pENW. In addition, pENW attenuated intracellular Ca2+ mobilization and TXA2 production in platelets stimulated by thrombin. As shown by Western blot assay, Akt, ERK and p38 phosphorylation in thrombin-induced platelet were attenuated by pENW. However, inhibitory effects of pENW had nothing to do with ROS. Thus, pENW exhibited a significant inhibition on platelet adhesion to fibrinogen, which means pENW could block the first step of thrombosis as while as retard the more stable clot formation. The mechanisms of pENW on inhibition platelet adhesion might be related to instant regulations, such as protein kinases.
Blood Platelets ; drug effects ; Blotting, Western ; Calcium ; metabolism ; Cyclic AMP ; metabolism ; Cyclic GMP ; metabolism ; Flow Cytometry ; Phosphorylation ; Platelet Aggregation ; drug effects ; Reactive Oxygen Species ; metabolism ; Snake Venoms ; chemistry ; Thromboxane A2 ; metabolism ; Thromboxane B2 ; metabolism

To evaluate the changes of 3', 5'-cyclic adenosine monophosphate (cAMP), thromboxane A2(TXA2) and prostacyclin (PGI2) in cerebrospinal fluid (CSF) in the asphyxiated newborn and explore their roles in hypoxic-ischemic brain damage (HIBD). Thirty-six full term newborns were divided into 3 groups, including 12 with moderate-severe hypoxic-ischaemic encephalopathy (HIE), 13 with mild HIE, 11 without HIE (control group). The levels of cAMP, TXB2 (TXA2 metabolite) and 6-keto-PGF1 alpha (PGI2 metabolite) in CSF and plasma were measured 36-72 h after birth by RIA, and the concentrations were expressed as nM/L (cAMP), ng/L(TXB2 and 6-keto-PGF1 alpha). The infants were followed-up at 6 and 12 month of age and Mental Development Index (MDI) and Psychomotor Development Index (PDI) were measured using Bayley Scales of Infant Development (BSID). The CSF cAMP level in moderate-severe HIE group was 8.60 +/- 2.40, significantly lower than that of the mild HIE group (14.83 +/- 2.84) and the control group (24.43 +/- 2.39) (for both P < 0.01). The levels of TXB2 and 6-keto-PGF1 alpha in CFS in the moderate-severe HIE group (206.06 +/- 29.74, 168.47 +/- 23.02, respectively) were significantly higher than in the mild HIE group (83.37 +/- 28.57, 131.42 +/- 16.57, respectively, P < 0.01) and the control group (41.77 +/- 21.58, 86.23 +/- 13.05, respectively, P < 0.01). The level changes of cAMP, TXB2 and 6-keto-PGF1 alpha in plasma in all groups were similar to those in CSF, but no significant difference was found between mild HIE group and the control group (P > 0.05). The follow-up results showed that MDI and PDI of the moderate-severe HIE group were the lowest (84.79 +/- 13.34, 83.50 +/- 13.28, respectively), followed by mild HIE group (102.19 +/- 7.02, 99.94 +/- 9.08, respectively), with the control group being the highest (116.63 +/- 12.08, 116.69 +/- 10.87, respectively). Univariate analysis showed some significant difference (the moderate-severe HIE group vs. the mild HIE group or the control group, P < 0.01; the mild HIE group vs. the control group P < 0.05). The results suggested that the concentration of cAMP, TXA2 and T/K ratio in CSF after neonatal asphyxia might be sensitive markers in evaluating the severity of brain damage in early stage and predicting the future outcome.
6-Ketoprostaglandin F1 alpha ; cerebrospinal fluid ; Asphyxia Neonatorum ; cerebrospinal fluid ; Biomarkers ; Cyclic AMP ; cerebrospinal fluid ; Epoprostenol ; cerebrospinal fluid ; Female ; Follow-Up Studies ; Humans ; Hypoxia-Ischemia, Brain ; cerebrospinal fluid ; Infant, Newborn ; Male ; Thromboxane A2 ; cerebrospinal fluid ; Thromboxane B2 ; cerebrospinal fluid

OBJECTIVETo study the change of vascular tension factors (VTF), including vascular contractile factors as endothelin-1 (ET-1), thromboxane A2 (TXA2) and vascular dilatory factors as nitric oxide (NO), prostacyclin (PGI2), in different stage of peripheral diabetic arterial occlusion (PDAO), and to preliminarily explore the clinical significance of these changes.

METHODSVTF in 40 diabetic patients, 15 of 2nd stage and 25 of 3rd stage, were observed by measuring level of ET-1, NO, TXB2 and 6-keto-PGF1alpha in blood plasma with RIA assay.

RESULTS(1) ET-1 and TXB2 levels in all patients were higher than those in control (P < 0.05 and P < 0.01), those in patients of 3rd stage was higher than those of 2nd stage, showing significant difference (P < 0.05). (2) NO and 6-keto-PGF1alpha levels in all patients was lower than those in control, but showed no significant difference between patients of various stages (P > 0.05).

CONCLUSIONThere are changes of VTF in patients with PDAO, manifesting as increase of vascular contractive factors and decrease of vascular dilative factor. The changes are diffrent in various stages, the vascular contractive and thrombotic factors in patients of 3rd stage are higher than those in patients of 2nd stage, but the injury on vascular dilative factors in the two stages showed insignificant difference.

6-Ketoprostaglandin F1 alpha ; blood ; Aged ; Aged, 80 and over ; Diabetes Mellitus, Type 2 ; metabolism ; Diabetic Angiopathies ; metabolism ; physiopathology ; Endothelin-1 ; blood ; Epoprostenol ; blood ; Female ; Humans ; Lower Extremity ; blood supply ; Male ; Middle Aged ; Nitric Oxide ; blood ; Thromboxane A2 ; blood ; Thromboxane B2 ; blood ; Vasomotor System ; metabolism

BACKGROUNDIt has been shown that neurohumoral factors other than mechanical obstruction are involved in the pathophysiology of acute pulmonary thromboembolism (APTE). The aim of this study was to investigate the effects of thrombolytic drugs, a selective endothelin-1 receptor (ET-1R) antagonist alone or their combination on APTE in a canine model.

METHODSTwenty dogs were randomly assigned to five groups: sham, model, urokinase (UK), BQ123, and combination (UK plus BQ123). The dogs in the sham group underwent sham surgery. APTE was induced in the other four groups by intravenous injection of autologous blood clots. Dogs in the UK, BQ123 and combination groups received UK, BQ123 (a selective ET-1R antagonist), or UK plus BQ123, respectively. The dogs in the model group were given saline. Mean pulmonary artery pressure (mPAP), serum concentrations of ET-1, thromboxane (TXB2), and tumor necrosis factor (TNF)-alpha were determined at different time points following the induction of APTE.

RESULTSUK and BQ123 alone markedly decreased mPAP in APTE. By comparison, the reduction was more significant in the combination group. Compared with the sham group ((-0.90 +/- 0.61) mmHg), mPAP increased by (7.44 +/- 1.04), (3.42 +/- 1.12) and (1.14 +/- 0.55) mmHg in the model group, UK alone and BQ123 alone groups, respectively, and decreased by (2.24 +/- 0.67) mmHg in the combination group (P < 0.01). Serum ET-1 concentrations in the BQ123 and combination groups were (52.95 +/- 8.53) and (74.42 +/- 10.27) pg/ml, respectively, and were significantly lower than those in the model and UK groups ((84.56 +/- 7.44) and (97.66 +/- 8.31) pg/ml respectively; P < 0.01). Serum TNF-alpha concentrations were significantly lower in the BQ123 group than in the model, UK and combination groups (P < 0.05).

CONCLUSIONSOur results indicate that the selective ET-1R antagonist BQ123 not only reduces the increase of mPAP and serum ET-1 level, but also inhibits the production of TNF-alpha, and attenuates the local inflammatory response induced by APTE. Selective ET-1R antagonists may be beneficial to the treatment of APTE, particularly when used in combination with a thrombolytic agent.

Animals ; Dogs ; Endothelin A Receptor Antagonists ; Endothelin-1 ; blood ; Fibrinolytic Agents ; therapeutic use ; Peptides, Cyclic ; therapeutic use ; Pulmonary Embolism ; blood ; drug therapy ; pathology ; Random Allocation ; Thromboxanes ; blood ; Tumor Necrosis Factor-alpha ; blood

BACKGROUNDAspirin is widely used in the secondary prevention of coronary artery diseases, including myocardial infarction, stroke, and vascular related deaths. However, the antiplatelet effect of aspirin appears to be variable and aspirin resistance (AR) is currently still controversial for Chinese patients. The aim of this study was to describe the prevalence of AR, and identify possible risk factors associated with a lack of response to aspirin treatments in patients with unstable coronary artery disease.

METHODSPlatelet function tests with arachidonic acid (ARA) and urinary 11-dehydro-thromboxane B2 (11-DH-TXB2) concentrations were performed in 262 patients with unstable coronary artery disease who had not been taking aspirin before admission. ARA induced platelet aggregation and 11-DH-TXB2 were detected to evaluate the functional and biochemical responses to aspirin before and on days 1, 4, and 10 after aspirin administration. Six-month follow-up was completed in patients who developed AR to evaluate the effect of aspirin in a long-term treatment. GP1Bα (C1018T), Pl (A1/A2), P2Y1 (A1622G), TBXA2R (T924C) were also detected to evaluate the influence of genetic variant on aspirin responsiveness.

RESULTSA total of 8.8% of patients were indentified as AR at the first day after aspirin treatment. The level of urine 11-DH-TXB2 in the AR group was higher compared to non-AR group (P < 0.05). There was no relationship between ARA induced platelet aggregation and urinary 11-DH-TXB2 levels (r = 0.038, P = 0.412). The results of DNA sequencing showed that TBXA2R-924TT homozygotes had a significantly high rate of AR. Logistic regression demonstrated that diabetes was an independent risk factor of AR.

CONCLUSIONSIn the beginning period of administration, aspirin was not a sufficient factor that inhibits platelet aggregation. TBXA2R-924T allele was involved in AR. Diabetes was an independent risk factor of AR.

Aged ; Aged, 80 and over ; Arachidonic Acid ; pharmacology ; Aspirin ; therapeutic use ; Coronary Artery Disease ; drug therapy ; genetics ; Diabetes Mellitus, Type 2 ; Female ; Genotype ; Humans ; Male ; Membrane Glycoproteins ; genetics ; Middle Aged ; Platelet Aggregation ; drug effects ; Platelet Aggregation Inhibitors ; therapeutic use ; Platelet Function Tests ; Platelet Glycoprotein GPIb-IX Complex ; Polymerase Chain Reaction ; Polymorphism, Genetic ; genetics ; Receptors, Purinergic P2Y1 ; genetics ; Receptors, Thromboxane A2, Prostaglandin H2 ; genetics ; Thromboxane B2 ; analogs & derivatives ; urine

No abstract available.
Dinoprost* ; Flurbiprofen* ; Gabexate* ; Prednisolone* ; Thromboxane B2*