Biomedical subjects

M Boros

Publications and source records attributed to M Boros.

At least 19 recordsLinked to original sources

PubMed2006

Surgical treatment of intercostal hernia with implantation of polypropylene mesh.

The intercostal hernia of the lung is a very rare extraordinary disease that requires operation because of the complaints and potential complications. The authors review cases of their operations and analyze the subsequence and treatment. Three patients have been treated for intercostal lung hernia in our treatment. The causes of this disease were a previous thoracotomy in one case and fits of coughing in the other two cases. The diagnosis was set up on the grounds of the specific clinical symptoms, thoracic X-ray and CT scan. The hernia was dissolved with percostal stitches and with the suture of the thoracic musculature in two cases. Plastic operation of the thoracic wall by implanting a polypropylene surgical mesh (Prolen, Ethicon, Johnson & Johnson) was performed in the case of the third patient and later in the first two patients due to recrudescence. In one case the authors were constrained to resect the dystelectasial lung in the hernial sac. The three patients had been operated five times. Relapse of hernia was detected in two patients, in whom the intercostal space had been reconstructed with percostal stitches. We did not detect any relapsing in those two patients at 33 and 66 months after the second operation with mesh implantation. The third patient who got mesh implant immediately did not relapse 12 months after the operation. Intercostal lung hernia is an indication of operation. A plastic operation of the thoracic wall combined with the implantation of a surgical mesh is recommended to close the hernial orifice, which is suitable for treating both primary and relapsed hernias. Recurrence is rare in those patients treated with this method.

Cough↗

PubMed2006

Pathophysiology of ischemia-reperfusion injury.

Our studies characterized the intestinal microcirculatory changes in canine models of intestinal hypoperfusion (hemorrhagic shock) or ischemia-reperfusion (small bowel autotransplantation). The villus microcirculatory parameters (functional capillary density, mean red blood cell velocity) were observed by intravital microscopy using orthogonal polarization spectral imaging. The leukocyte reaction (rolling and firm adherence) in the mesentery was quantified by using conventional fluorescence videomicroscopy. The investigations were aimed at determining whether the compromised intestinal villus perfusion could be influenced by endothelin-A receptor inhibition, volume resuscitation, or ischemic preconditioning. The results demonstrated the pathophysiological significance of endothelin-A receptor activation in ischemia-reperfusion-induced microcirculatory changes. Second, it was shown that colloid fluid therapy with hydroxyethyl-starch effectively ameliorated the microcirculatory consequences of hypovolemia, which correlated with a lower endothelin release. Third, ischemic preconditioning when applied 60 minutes before ischemia, inhibited the reperfusion-induced superoxide production, improved capillary perfusion, and attenuated leukocyte activation within the intestinal graft. Among the examined therapeutic strategies aimed at improving the outcome of intestinal microcirculatory dysfunction, endothelin-A receptor antagonist pretreatment and ischemic preconditioning are promising tools to decrease the harmful consequences of ischemia/reperfusion.

Animals↗

PubMed2006

Two-stage hepatectomy: an analysis of a single center's experience.

Hepatic resection remains the only potential curative treatment for either primary or secondary liver tumors. In order to increase the resectability of initially unresectable tumors and to decrease the posthepatectomy morbidity and mortality, ligation and section of a portal branch with consecutive hepatic resection is recommended. Between September 1st 1999 and January 1st 2006, in the Department of General Surgery and Liver Transplantation of Clinical Institute Fundeni (Bucharest), the ligation of a portal branch was performed in 15 patients with gross hepatic tumors: hepatocellular carcinoma (2 cases), peripheral cholangiocarcinoma (6 cases) and hepatic metastases for colorectal cancer (7 cases). Two-stage hepatectomy was performed in 8 cases. The interval between the two operations ranged between 4 weeks and 2 months (except one case that returned to us only after 6 months, when was reevaluated and resected). Hepatic resection could not be performed in 7 cases due to the local and regional progression of the disease (4 cases) or to the absence of the hypertrophy-atrophy process (3 cases). In the 8 resected cases, hepatic failure occurred posthepatectomy in 2 patients, resulting in the death of one patient; that means a mortality of 12.5%. Other two patients died at 4 and 10 months respectively, as a result of distant metastases. The rest of 5 patients are alive, free of recurrence; two of them have more than 5 years from the operation. CONCLUDING: portal vein ligation can be performed in selected cases of unresectable gross hepatic tumors. Two-staged hepatectomy is not always feasible. Moreover, the hypertrophy of the contralateral lobe does not always prevent the postoperative hepatic failure. For the cases that can be resected, both survival and quality of life are significantly improved.

Female↗

PubMed2005

Esophageal ATP synthase and keratinocyte growth factor gene expression changes after acid and bile-induced mucosal damage.

OBJECTIVE AND DESIGN: Intramural gene expression changes may be critically involved in tissue damage, defense and repair after esophageal regurgitation. The aims were to characterize the consequences of short-term exposure to luminal bile, acid, or bile mixed with acid on the beta-ATPase, keratinocyte growth factor 1 (KGF-1) and KGF receptor (KGF-R) expressions within the mucosa and the muscle layer in a large animal model. MATERIALS AND SUBJECTS: Esophageal segments of anesthetized dogs were exposed to saline (n = 3), diluted canine bile (n = 6), hydrochloric acid (n = 5) or bile + hydrochloric acid (n = 5), and tissue biopsies were taken at the end of the 180-min observation period. Semiquantitative reverse transcriptase polymerase chain reactions were carried out and the degree of histological damage was evaluated on the 0-16-grade Geisinger scoring scale. RESULTS: Acid exposure was followed by a significant decrease in the level of beta-ATPase expression in the mucosa, and parallel increases in KGF-1 and KGF-R expression. Corresponding changes in the muscle layer were not significant. Bile alone evoked more severe tissue damage, with significantly decreased beta-ATPase levels in both the mucosa and the muscle, whereas the KGF-1 expression did not change significantly. The bile + acid treatment induced an intermediate state, with significant beta-ATPase transcription level decreases in both layers, while the mucosal KGF-1 expression was lower than that following acid treatment alone. CONCLUSIONS: The acid-induced transcriptional level downregulation of mucosal beta-ATPase gene expression in the smooth muscle layer was exacerbated by bile, but the concomitant KGF and KGF-R gene expression changes may indicate the start of a consecutive repair process.

ATP Synthetase Complexes↗

PubMed2004

The role of the glucocorticoid-dependent mechanism in the progression of sodium taurocholate-induced acute pancreatitis in the rat.

The effects of glucocorticoids on acute pancreatitis (AP) have remained contradictory. The aim of this study was to investigate the time courses of the effects of the exogenous glucocorticoid agonists dexamethasone (DEX) and hydrocortisone (HYD) and a glucocorticoid antagonist (RU-38486) and to characterize the local and systemic responses in AP in rats. The glucocorticoid antagonist and agonists were administered just before AP induction. Serum amylase activity determinations, IL-6 bioassays, pancreatic weight/body weight ratio measurements, and survival analysis were performed. Liver and lung injuries were assessed via neutrophil leukocyte infiltration in myeloperoxidase (MPO) assays, tissue adenosine triphosphate (ATP) level determinations, and histology. In the glucocorticoid agonist groups, the survival rate increased, while the serum amylase level, the IL-6 activity, and the pancreatic weight/body weight ratio decreased significantly as compared with the control and RU-treated groups. AP resulted in significant decreases in tissue ATP levels in both the liver and the lung. In the DEX- or HYD-treated groups, the liver ATP levels were significantly elevated, while both the liver and the lung MPO levels were attenuated as compared with the AP and RU-treated groups. These results suggest that glucocorticoids may play important roles in mitigating the progression of the inflammatory reaction during the early phases of AP.

Acute Disease↗

PubMed2003

Microcirculatory changes in the canine oesophageal mucosa during experimental reflux oesophagitis: comparison of the effects of acid and bile.

BACKGROUND: The response of the oesophageal microcirculation to luminal damaging agents may play an important role in reflux-induced mucosal injury. We characterized the microcirculatory consequences of exposure to bile with or without hydrochloric acid, and determined the changes in the constitutive nitric oxide synthase and inducible nitric oxide synthase activities in a canine model of acute reflux oesophagitis. METHODS: Group 1 served as a saline-treated control, while groups 2-4 were exposed for 3 h to bile alone, to hydrochloric acid, or to bile + hydrochloric acid, respectively. The mucosal microcirculation was observed continuously by means of intravital videomicroscopy with an orthogonal polarization spectral imaging technique. Myeloperoxidase, constitutive and inducible nitric oxide synthase activities were measured via tissue biopsies, while the degree of mucosal damage was evaluated histologically. RESULTS: Bile evoked deep tissue damage and leucocyte accumulation in the mucosa and muscle layer. The capillary red blood cell velocity and the relative vessel area increased significantly (P < 0.05). The constitutive NO synthase activity was decreased, and the inducible NO synthase activity was increased significantly. In the hydrochloric acid-treated group the functional capillary density decreased, the mucosal damage was less severe, the constitutive NO synthase activity did not change, whereas the inducible NO synthase activity was increased significantly. The constitutive NO synthase activity did not change after the bile + hydrochloric acid treatment either. CONCLUSION: Reflux components induce characteristic microcirculatory alterations. The structural damage and leucocyte invasion are accompanied by bile-induced constitutive NO synthase inhibition when hydrochloric acid production is suppressed.

Acute Disease↗

PubMed2003

Microcirculatory dysfunction during intestinal ischemia-reperfusion.

Oxido-reductive stress is a crucial factor of the tissue response during ischemia-reoxygenation injuries. Reperfusion affects primarily the microvasculature in a manner consistent with an acute inflammatory reaction. In this respect, the salient data suggest an important connection between endothelial cell-derived humoral mediators and the perivascular mast cell system. Increased endothelin-1 and decreased nitric oxide formation, mast cell degranulation and leukocyte accumulation coexist in gastrointestinal ischemia-reperfusion syndromes too. Constitutively produced nitric oxide inhibits, while increasingly formed endothelin-1 significantly enhances the degranulation of the intestinal mast cells. The endothelin-A receptor-dependent mast cell degranulation per se plays a secondary role in reperfusion-induced structural injury, but contributes significantly to leukocyte recruitment into the reperfused intestinal mucosa. It is conceivable therefore, that the nitric oxide--endothelin-1--mast cell cycle is involved in the mechanism of ischemia-reperfusion-induced endothelial cell-leukocyte interactions, where mast cells act to amplify the process of leukocyte sequestration. The alteration in the balance between endothelial cell-derived proadhesive vasoconstrictor and antiadhesive vasodilator factors exerts a significant influence on the mucosal integrity, and the antagonism of endothelin-A receptor activation in this setting tips the equilibrium toward tissue salvage.

Animals↗

PubMed2002

Kupffer cell phagocytosis blockade decreases morbidity in endotoxemic rats with obstructive jaundice.

OBJECTIVE AND DESIGN: The consequences of Kupffer cell phagocytosis blockade were studied in endotoxemic rats with obstructive jaundice. MATERIAL OR SUBJECTS: 159 male Wistar rats. TREATMENT: Obstructive jaundice was induced by bile duct ligation (BDL). Gadolinium chloride (1 mg/100 g iv) was given 6 days after BDL to inhibit Kupffer cell activity and the animals were challenged with 1 microg/g endotoxin 24 h later. METHODS: Endotoxin sensitivity, tumor necrosis factor-alpha and interleukin-6 production were studied, liver and lung injury were assessed by neutrophil infiltration assay, tissue adenosine triphosphate, aspartate aminotransferase, alanine aminotransferase level determinations and histology, respectively. For statistics non-parametric methods were used. RESULTS: BDL sensitized the animals to endotoxin, increased endotoxin-induced tumor necrosis factor-alpha and interleukin-6 production and reduced ATP contents of the liver and the lung. Kupffer cell blockade significantly increased the resistance against endotoxin, diminished the inflammatory cytokine release and reduced endotoxin-induced tissue injury in BDL animals. CONCLUSION: Attenuation of Kupffer cell function decreases endotoxin-induced lethality and morbidity in obstructive jaundice.

Adenosine Triphosphate↗

PubMed2001

[Methods for in vivo investigation of human microcirculation].

Microcirculatory disorders play a major role in the development of organ failure in a variety of conditions. Perfusion changes may be visualized by static and dynamic methods, with direct and indirect techniques. Orthogonal polarization spectral imaging is a novel method of imaging the human microcirculation. The technique employs reflected light without fluorescent dyes and allows clinical assessment of the dynamic of the microvascular network of internal solid organs. Principles of the technique and indications of use are briefly discussed.

Capillaries↗

PubMed2001

Electrophilic methyl groups present in the diet ameliorate pathological states induced by reductive and oxidative stress: a hypothesis.

Reductive stress, characterised by an increased NADH:NAD+ ratio, may be as common and as important a consequence of redox imbalance as oxidative stress. It may also be an important predisposing cause of the generation of reactive oxygen species. Considerable experimental and indirect clinical evidence suggests that protection against reductive stress depends on biomolecules with electrophilic methyl groups (EMG) such as S-adenosylmethionine, betaine, carnitine and phosphatidylcholine. Pathological processes leading to reductive stress and their relief by such protective agents is reviewed and the proposed molecular mechanism is outlined. These and other EMG-containing biomolecules are part of the daily diet and may represent an important control system for redox balance.

Alcoholic Intoxication↗

PubMed2001

Bile-induced adenosine triphosphate depletion and mucosal damage during reflux esophagitis.

BACKGROUND: This study was designed to investigate the role of bile in a large animal model of acute esophageal reflux disease. METHODS: An agar electrode was used to measure the transmucosal potential difference of the esophagus in anaesthetized dogs. The vascular permeability index and the epithelial permeability index of the mucosa were evaluated by means of the Evans blue and the sodium-fluorescein clearance method, respectively. The tissue adenosine triphosphate (ATP) level and the myeloperoxidase activity were determined from tissue biopsies, while the degree of mucosal damage was evaluated histologically on a grade 0-100 scale. Group 1 (n = 8) served as saline-treated control; groups 2 (n = 8), 3 (n = 5) and 4 (n = 5) were exposed for 4 h to canine bile alone, to hydrochloric acid + bile, or to hydrochloric acid alone, respectively. RESULTS: In Groups 2, 3 and 4 the degree of mucosal damage was significantly increased, and a 4-fold elevation in myeloperoxidase activity was observed. The transmucosal potential difference was decreased significantly below the control level, while the vascular and epithelial permeability indices were significantly increased compared with the control values. Bile, but not hydrochloric acid, evoked a significant (40%) decrease in the ATP level of the esophageal tissue. CONCLUSIONS: We propose that mucosal dysfunction, structural damage and leukocyte invasion during hydrochloric acid-induced esophageal injury are exacerbated by bile-induced changes in tissue ATP concentrations during experimental esophageal reflux disease.

Acute Disease↗

PubMed2001

Betaine-palmitate reduces acetylsalicylic acid-induced gastric damage in rats.

BACKGROUND: Acetylsalicylic acid (ASA)-induced gastric injury is reduced when ASA is administered along with phosphatidylcholine. The hydrolysis of endogenous phosphatidylcholine leads to the production of betaine, which may participate in the maintenance of cellular homeostasis. The present aims were to investigate the effects of exogenous betaine and its palmitic acid complex (betaine-palmitate) in the protection of the gastric mucosa in ASA-induced subacute damage. METHODS: Repeated doses of ASA were given intragastrically to male Wistar rats. Control rats were given vehicle only, while treated animals were challenged with ASA or with ASA along with betaine, palmitic acid or betaine-palmitate. The gastric mucosa was examined after 3 days and the nature of any microscopic mucosal injury was assessed by histology. The extent of macroscopic damage, changes in permeability (assessed by Evans blue method) and tissue ATP concentrations were determined in separate series. RESULTS: ASA induced a significant fall in the ATP content of the mucosa, which was not affected by the other drugs used in the study. However, the ASA-induced mucosal permeability increase could be completely reversed by betaine-palmitate supplementation. The extent of severity of the macroscopic and microscopic lesions was 33% and 2.45, respectively, for ASA, as compared with 15% and 2.2 for betaine, 14% and 1.9 for palmitic acid and 3% and 1.4 for betaine-palmitate. CONCLUSIONS: Betaine-palmitate affords a significant protective effect against ASA-induced injury, without influencing the ATP synthesis, and this suggests that the defence is due to its ability to prevent secondary damage.

Animals↗

PubMed2001

Endothelin-1-induced airway and parenchymal mechanical responses in guinea-pigs: the roles of ETA and ETB receptors.

Endothelin-1 (ET-1) has been shown to have a constrictor effect on the airways and parenchyma; however, the roles of the ETA and ETB receptors in the ET-1-induced changes in the airway and tissue compartments have not been fully explored. Low-frequency pulmonary impedance (ZL) was measured in anaesthetized, paralysed, open-chest guinea-pigs. ZL spectra were fitted by a model to estimate airway resistance (Raw) and inertance (Iaw), and coefficients of tissue damping (G) and elastance (H), and hysteresivity (eta = G/H). Two successive doses of ET-1 (0.05 and 0.2 nmol x kg(-1)) each evoked significant dose-related increases in Raw, G, H and eta. Pretreatment with 20 nmol x kg(-1) BQ-610 (a highly selective ETA receptor antagonist) resulted in a significantly decreased elevation only in H after the lower dose of ET-1. However, all parameters changed significantly less on the administration of ET-1 after pretreatment with 80 nmol-kg(-1) BQ-610, with 20 nmol x kg(-1) ETR-P1/fl (a novel ETA receptor antagonist) or with 20 nmol x kg(-1) IRL 1038 (an ETB receptor antagonist). The results of the separate assessments of the airway and tissue mechanics demonstrate that endothelin-1 induces airway and parenchymal constriction via stimulation of both receptor types in both compartments.

Airway Resistance↗

PubMed2001

Intravital microscopic assessment of pressure induced microcirculatory changes after enterocystoplasty in rats.

PURPOSE: Chronic over distention may lead to enterocystoplasty rupture. It is hypothesized that pressure induced microvascular derangement and subsequent ischemia of the enterocystoplasty intestinal patch may have a role in this process. We describe distention induced microcirculatory alterations in a chronic rat model of enterocystoplasty using intravital video microscopy. MATERIALS AND METHODS: Microcirculation in the muscle layer of the intact bladder and intestine, and in the enterocystoplasty 90 days after surgery were examined at greater and less than urethral sphincter closure pressure. Microcirculatory changes were recorded during stepwise increments of intraluminal pressure up to 80 mm. Hg or when 20 mm. Hg was continuously maintained for 60 minutes. RESULTS: The enterocystoplasty components of intestine and bladder displayed baseline microcirculatory characteristics similar to those observed in the intact organs. As evidenced by microcirculatory flow and functional capillary density measurements in the intact intestine and the ileal portion of enterocystoplasty, intraluminal pressure elevation to greater than 25 or 30 mm. Hg significantly compromised capillary perfusion by approximately 50% and 75%, respectively. Lower intraluminal pressure did not cause microcirculatory disturbance even when maintained for a longer period. In the intact bladder and bladder portion of enterocystoplasty only pressure increases to greater than 80 mm. Hg affected tissue perfusion. CONCLUSIONS: Intravital microscopy in the augmented rat bladder is a sensitive and suitable means of assessing clinically relevant microcirculatory changes. These experiments demonstrate the significance of distention induced microcirculatory impairment in the intact bowel and the intestinal site of enterocystoplasty even at less than urethral closure pressure.

Animals↗

PubMed2001

[Use of crystal conversion reactions in the synthesis of pentacyclic alkaloid analogues].

During investigation of substitution of debenzorutaecarpine derivatives thermal cyclization reactions was observed to produce new fused heterocyclic systems. The optimal temperature of cyclizations was determined by differential calorimetric measurements of crystals of intermediate products. The thermolysis of 2-azido-3-formil-debenzorutaecarpine gave, after elimination nitrogen, izooxazolo-debenzorutaecarpine in good yield. The cyclization of the 2-azido-3-nitroso-debenzorutaecarpine readily led to oxadiazolo E-ring analogue of rutaecarpine. The thermal cyclization of 2-hydroxy-debenzorutaecarpines gave 2-oxo- and 4-oxo-pyrano E-ring analogues of rutaecarpine. The structure of substances was confirmed by spectroscopic methods. The synthesised compounds are considered as first representatives of new heterocyclic ring systems.

Alkaloids↗

PubMed2000

Endothelin-1 induces mucosal mast cell degranulation in the rat small intestine.

The enhanced production of endothelial cell-derived vasoactive mediators and the activation of mast cells (MCs) have been implicated in the pathogenesis of mucosal damage during ischemia and reperfusion injuries. The first objective of our study was to define the in vivo relation between endothelin-1 (ET-1) and the MC system. Secondly, we determined whether pretreatment with ET receptor antagonists would attenuate MC responses to exogenous ET-1. In the first series of experiments, increasing doses of ET-1 (0. 1, 1 and 3 nmol/kg i.v.) were administered to anesthetized rats. In the second series, the animals were pretreated with equimolar doses of the ET-A receptor antagonist BQ-610 or ETR-P1/fl peptide, and the ET-B receptor antagonist IRL-1038. Intestinal perfusion changes and macrohemodynamics were recorded, and the proportion of degranulated MCs was determined in ileal biopsies. The average mucosal thickness was recorded with an image analysis system. ET-1 induced dose-dependent alterations in the hemodynamic and morphological parameters and caused pronounced mucosal injury, with a significant reduction in villus height. The ratio of degranulated MCs was similar in all ET-treated groups (77%, 82% and 86%) to that observed in animals subjected to 15-min ischemia and 60-min reperfusion (85% degranulation). Pretreatment with BQ-610 and ETR-P1/fl peptide attenuated the ET-1 induced alterations in the hemodynamic parameters and decreased structural injury to the mucosa. ET-induced MC degranulation was significantly inhibited by the ET-A receptor antagonists, but not by IRL-1038. These results indicate that elevated levels of circulating ET-1 might induce intestinal mucosal tissue injury and MC degranulation via activation of ET-A receptors, and raise the possibility that ET-A receptor antagonist administration could exert a potentially beneficial effect through a mechanism other than the blockade of vasoconstriction in pathologies associated with an increased ET-1 release.

Amino Acid Sequence↗

PubMed2000

Prevention of early myocardial depression in hyperdynamic endotoxemia in dogs.

In our study the pathomechanism of sepsis-induced early myocardial depression was investigated. We determined the effects of the inducible nitric oxide synthase inhibitor and free radical scavenger mercaptoethylguanidine (MEG) on the myocardial contractility, the endothelial and inducible nitric oxide synthase (eNOS and iNOS) activities, and the activation and tissue accumulation of polymorphonuclear leukocytes in hyperdynamic endotoxemia in dogs. Group 1 served as endotoxemic control. Mean arterial pressure and cardiac output were measured, myocardial contractility was estimated from the end-systolic pressure-diameter relationship. The eNOS, iNOS and myeloperoxidase activities were determined on myocardial biopsy samples, and the free radical-producing capacity of granulocytes was measured from separated cells. The effect of MEG on the in vitro free radical production of isolated granulocytes was measured by chemiluminometry. Endotoxin induced a hyperdynamic circulatory reaction and significant myocardial depression. The myocardial eNOS activity was significantly increased 4 h after induction of endotoxemia and remained elevated, the iNOS activity was increased only 8 h after endotoxemia induction. The free radical-producing capacity and the myocardial accumulation of the granulocytes were significantly increased. In group 2, MEG treatment selectively inhibited the iNOS activity, prolonged the hyperdynamic circulatory reaction, prevented myocardial depression and decreased the activation and tissue accumulation of granulocytes. The compound dose-dependently decreased the in vitro activation of previously resting granulocytes. Our study demonstrates that iNOS do not contribute to the early cardiac failure in endotoxemia. MEG selectively inhibits iNOS in vivo, but its beneficial effects are rather related to the decreases in leukocyte and free radical-mediated myocardial dysfunction during early endotoxemia.

Animals↗

PubMed2000

[The role of nitric oxide synthase, and of granulocytes, in endotoxin-induced early myocardial depression].

UNLABELLED: The aim of our study was to investigate the role of endothelial and inducible nitric oxide synthase (eNOS and iNOS) and granulocytes during hyperdynamic endotoxemia, and to study the cardiovascular effects of the non-selective NOS-inhibitor N-omega-nitro L-arginine methylester (L-NAME) and the selective iNOS-inhibitor mercaptoethylguanidine (MEG) in the early myocardial depression. METHODS: Endotoxemia was induced in anesthetized dogs. Mean arterial pressure, cardiac output and peripheral vascular resistance was monitored, left ventricular contractility was calculated. Myocardial eNOS and iNOS activities and myeloperoxidase (MPO) activity, as the marker of granulocyte infiltration were determined from tissue biopsy samples. RESULTS: Endotoxemia was accompanied by a short hyperdynamic circulatory reaction, hypotension and myocardial depression. We observed an early increase in eNOS and a late increase in iNOS activity. MPO activity increased significantly after 8 hr endotoxemia, suggesting considerable granulocyte-extravasation. Non-selective NOS-inhibition prevented hypotension, exerted positive inotropic effect, but induced a rise in peripheral vascular resistance and a further increase in myocardial MPO activity. MEG treatment stabilized myocardial contractility on the control level, increased cardiac output and attenuated tissue granulocyte infiltration. CONCLUSIONS: The increased activity of eNOS and granulocyte infiltration may be responsible for the early cardiac depression during endotoxemia. Non-selective NOS-inhibition has beneficial effects, but is also induces side-effects by disturbing vasoregulation. Selective iNOS-inhibition has no significant hemodynamic effects during early endotoxemia, but restores cardiac efficacy probably through attenuating granulocyte-associated myocardial dysfunction.

Animals↗