Feline endotoxin shock: effects of methylprednisolone on kininogen-depletion, on the pulmonary circulation and on survival

Differential proteomics of the plasma of individuals with sepsis caused by Acinetobacter baumannii

This study examines alterations in the plasma proteome in ten adults affected by sepsis caused by Acinetobacter baumannii as compared to paired healthy controls. 2-DE profiles of plasma from patients and paired healthy donors, depleted of the six most abundant proteins, were analysed by the DIGE technique. Protein spot detection and quantification were performed with the Differential In-gel Analysis and Biological Variation Analysis modules of the DeCyder() software. Differentially expressed proteins were identified by mass spectrometry (MALDI-TOF/TOF) after colloidal Coomassie blue staining. Almost 900 spots were detected on a unique 2-D gel by the DIGE technique. A total of 269 protein spots of differential abundance were shown to be statistically significant (2.5-fold) with p values of p< or =0.01 (135 spots) and p< or =0.05 (134 spots) as determined by the t test. Seventy-one spots were submitted to mass spectrometry and about 30% could be successfully identified. This multiplex approach significantly reduced experimental variability, allowing for the confident detection of small differences in protein levels. Results include differentially expressed lipoproteins as well as proteins belonging to inflammatory/coagulation pathways and the kallikrein-kinin system. These data improves the knowledge for future developments in sepsis diagnosis, staging and therapy.

Comparison of responses of canine pulmonary artery and vein to angiotensin II, bradykinin and vasopressin

Responses to angiotensin II, bradykinin and arginine vasopressin were compared in helical strips of canine pulmonary arteries and veins. Angiotensin II contracted the artery but relaxed the vein strip. The artery contraction was augmented by indomethacin and aspirin and was abolished by losartan. The vein relaxation was not affected by endothelium denudation but was abolished by the cyclooxygenase inhibitors, a prostaglandin I2 synthase inhibitor and losartan. The bradykinin-induced artery relaxation was inhibited by endothelium denudation, NG-nitro-L-arginine (L-NA) or indomethacin and abolished by their combined treatment. The vein relaxation produced by bradykinin was endothelium-independent and was abolished by indomethacin. Vasopressin produced a slight relaxation in the arteries, which was abolished by endothelium denudation and L-NA. The vein relaxation produced by vasopressin was abolished by endothelium denudation and combined treatment with L-NA and indomethacin. It may be concluded that (1) activation of angiotensin AT1 receptor subtype in smooth muscle produces contraction and also relaxation due to prostaglandin I2 release; the former predominates over the latter in the artery, whereas only the latter is operative in the vein, (2) the bradykinin-induced relaxation is due to nitric oxide (NO) from the endothelium and prostaglandin I2 from subendothelial tissues in the artery and solely to prostaglandin I2 in the veins, and (3) the vasopressin-induced relaxation is mediated by endothelial NO in the artery, and NO and prostaglandin I2 in the vein.

Renal kinin and kallikrein excretion in cirrhotic patients

Urinary kinin and urinary kallikrein activity were measured in 33 liver cirrhotics, and the values were correlated with the severity of the liver disease. A significant relationship was observed between urinary kinin excretion and urinary kallikrein excretion (r = 0.53; p less than 0.01). Both urinary kinin and kallikrein excretion were significantly lower in Child's group C than in Child's groups A and B (p less than 0.05) and showed positive correlations with serum albumin (r = 0.47, p less than 0.01 and r = 0.46, p less than 0.01, respectively). Increases in urinary kinin and kallikrein excretion after endoscopic variceal sclerotherapy were observed in 18 patients (p less than 0.01 and p less than 0.05, respectively). These results suggest that the renal kallikrein-kinin system in suppressed in severe liver disease in proportion to the severity of the underlying liver disease. In this study possible activation of this system after sclerotherapy was also demonstrated.

Effects of endoscopic variceal sclerotherapy using GT XIII on blood coagulation tests and the renal kallikrein-kinin system

Forty-six sclerotherapy sessions were performed on liver cirrhotics with high-risk esophageal varices using GT XIII, a sclerosant composed of gelatin, thrombin and coagulation factor XIII. GT XIII was effective for the prevention of temporary symptoms and transient hypotension observed in 55 sclerotherapy sessions using thrombin. In 42 (91%) sessions, patients underwent sclerotherapy with no symptoms, and in the other four (9%) sessions, only slight symptoms of general fatigue and headache were observed. Changes in the mean arterial pressure were significantly smaller in sessions using GT XIII than in those using thrombin (-12.3 +/- 13.6 vs. -26.8 +/- 20.7 mmHg, P less than 0.01). Changes in coagulation tests, similar to those of disseminated intravascular coagulation (DIC), were also reduced in sessions using GT XIII. Urinary kallikrein and kinin excretion significantly increased after the procedure (P less than 0.01), indicating activation of the renal kallikrein-kinin system. Increases in urinary kallikrein and kinin excretion showed a significant relationship with the consumed plasma fibrinogen levels (r = -0.51, P less than 0.01 and r = -0.58, P less than 0.01, respectively), and it was suggested that activation of the glandular kallikrein-kinin system caused by abrupt DIC-like changes in the hemostatic system might play a role in manifestations of temporary complications occurring with the use of hemostatic agents containing thrombin.

Modification by steroids of pulmonary oedema and prostaglandin E2 pharmacokinetics induced by endotoxin in rats

1. A single i.p. injection of bacterial endotoxin in rats (3.5 mg kg-1) caused lung injury assessed as changes in lung dry:wet weight ratio and leukopaenia over the subsequent 28 h. 2. This treatment also slowed the efflux of 14C from [14C]-prostaglandin E2 (PGE2), i.e., increased t1/2 and increased the survival of PGE2 in isolated perfused lungs over the same period. 3. These effects of endotoxin were reversed by methylprednisolone (30 mg kg-1), given 30 min after the endotoxin. 4. Another synthetic corticosteroid, budesonide (1.2 mg kg-1) given 1 h before endotoxin partially prevented the lung injury and leukopaenia but did not affect the increased t1/2 for PGE2 nor its survival. 5. The reversal by methylprednisolone of both the physical signs of lung injury and the changes in PGE2 pharmacokinetics caused by endotoxin suggests that changes in PGE2 pharmacokinetics could serve as an index of acute lung injury following sepsis.

Effects on peritoneal proteolysis and hemodynamics by high doses of methyl-prednisolone in experimental acute pancreatitis

Acute pancreatitis was induced in 15 anesthetized pigs by injection of Na-taurocholate into the pancreatic duct. Seven animals were pretreated with methyl-prednisolone sodium succinate 30 mg/kg intravenously. Using chromogenic peptide substrate assays, values of trypsin (TRY), plasma prekallikrein (PKK), plasma kallikrein (KK) and functional plasma kallikrein inhibition capacity (KKI) were studied in the peritoneal exudate. Cardiac output (CO) and arterial pressure (AP) were regularly monitored before and during a six hour observation period. In acute untreated pancreatitis a 40% reduction of PKK levels was found paralleled by an increased KK activity and a reduction of KKI capacity. High TRY levels were found in several animals. The mortality rate was 63%. The pretreated animals all survived. CO and AP were significantly less reduced than in the untreated animals. Components of the plasma kallikrein-kinin system and TRY in the exudate remained mainly unchanged. Methyl-prednisolone given as pretreatment significantly improves hemodynamic parameters and increases the survival rate. Methyl-prednisolone suppresses generation of trypsin activity and activation of the plasma kallikrein-kinin system in the peritoneal exudate which may be of significant importance to the outcome.

The effects of the protease inhibitor, aprotinin, on the course of shock induced by endotoxin in cats

The administration of endotoxin derived from Escherichia coli to anaesthetized cats resulted, within the first 5 min, in an initial increase in right atrial pressure and a reduction in systemic arterial blood pressure. Over the next 2 h shock was characterized by a reduced cardiac output, tachycardia, reduced arterial pH and an increased level of lactate. The survival rate at the end of the 8 h experimental period was only 10%. The protease inhibitor aprotinin (Trasylol), given as a continuous intravenous infusion 1000 kallikrein inhibitor units (k.i.u.) kg-1h-1 together with a bolus of 40,000 k.i.u. kg-1, significantly inhibited the severity and incidence of the initial endotoxin response (increase in right atrial pressure and systemic hypotension), perhaps suggesting the direct or indirect involvement of kinins. Aprotinin did not reduce the delayed effects of endotoxin (sustained reduction in cardiac output, lacticacidosis), nor did it improve survival at 8 h. Indeed, there was some evidence that aprotinin exaggerated the delayed effects of endotoxin in this model.

A comparison of the cardiovascular effects of dobutamine and a new dopamine derivative (D4975) during shock induced by E. coli endotoxin

1 The effects of a newly developed dopamine-xanthine derivative, 7-propyl-theophylline-dopamine (D4975) and of dobutamine have been examined in anaesthetized cats before and after the induction of shock with E. coli endotoxin. 2 Both D4975 and dobutamine caused dose-related increases in left ventricular (LV) dP/dtmax (and LVdP/dt at fixed isovolumic pressures. Significantly smaller increases in LVdP/dtmax occurred as early as 0.5 to 1 h after endotoxin, with maximal attenuation at 1 to 2 h and some improvement in sensitivity in cats surviving 2 to 4 h. The maximum response to each drug was markedly reduced in shock. 3 Neither D4975 nor dobutamine had significant effects on heart rate. D4975 caused dose-related increases in systemic arterial blood pressure which were smaller during shock, the changes in responsiveness following those in LVdP/dtmax. 4 Possible mechanisms responsible for changing myocardial sensitivity to these and other agents are discussed. It is concluded that D4975 may be more useful in the treatment of shock than either dopamine or dobutamine because (a) it is more potent during shock than dobutamine (perhaps as a result of phosphodiesterase inhibition by the theophylline component of D4975); (b) its action is longer-lasting than dobutamine or dopamine and (c) like dobutamine, its effect on heart rate is insignificant.

Haemodynamic effects of the carboxylic ionophore monensin when administered before and during shock induced by E. coli endotoxin

The haemodynamic effects of the carboxylic ionophore monensin have been examined in cats anaesthetized with sodium pentobarbitone. Marked increases in left ventricular dP/dtmax (and dP/dt at fixed isovolumic pressures) and slight increases in cardiac output and stroke volume occurred, indicating increased myocardial contractility. Heart rate was unchanged but systemic arterial pressure was substantially increased. Satisfactory increases in contractility and arterial pressure were obtained when monensin was infused intravenously in a total dose of 0.25 mg kg-1 over 10 min. Larger doses, especially if rapidly injected, resulted in very marked increases in myocardial contractility leading eventually to cardiac failure. The haemodynamic effects of monensin were markedly reduced during shock induced by E. coli endotoxin and there was unfortunately no evidence to suggest that this extremely potent compound might be potentially beneficial in this form of profound cardiovascular shock.