Biomedical subjects

A Wykretowicz

Publications and source records attributed to A Wykretowicz.

At least 19 recordsLinked to original sources

PubMed2005

Augmentation index, pulse pressure amplification and superoxide anion production in patients with coronary artery disease.

BACKGROUND: Free oxygen radicals appear to be involved in several processes that contribute to atherogenesis and increased arterial stiffness. METHODS: The aim of our study was to evaluate arterial stiffness and the production of superoxide anions by activated polymorphonuclear neutrophils (PMN) obtained from patients with stable coronary artery disease (CAD). Thirty four consecutive patients were studied (21 men, 13 women, mean age 58 years) who underwent coronary angiography. Arterial stiffness was assessed by pulse wave analysis using a validated system (Sphygmocor Mx, AtCor Medical). Superoxide anion production by activated neutrophils was determined by a spectrophotometric method involving the measurement of cytochrome C reduction. The extent of coronary narrowing was estimated by calculation of the Gensini score. RESULTS: Superoxide anion production by stimulated PMN showed a significant positive correlation with the augmentation index (AIx) and a significant negative correlation with pulse pressure amplification (PPA), (r=0.4, p=0.02; r=-0.5 and p=0.0026 respectively). In multivariable analyses, after adjustment for age, gender and Gensini score, superoxide anions and BMI were significant predictors of AIx (R2=57.37%, p=0.001) and PPA (R2=49.04%, p=0.008). Superoxide anion production was significantly higher in the middle (52.0+/-5.8 nmol O2-/2.5x10(6) PMN/30 min) and upper teriles (62.7+/-5.6) of AIx in comparison with the first tertile 31.8+/-4.1 (p< or =0.05, p< or =0.001). Moreover, superoxide anion production in the highest tertile of PPA was significantly lower (35.6+/-4.3 nmol O2-/2.5x10(6) PMN/30 min) than that in the tertile (60.8+/-6.2, p< or =0.05). Neither the augmentation index nor pulse pressure amplification correlate with the severity of coronary atherosclerosis as indicated by the Gensini score. CONCLUSIONS: markers of arterial stiffness, AIx and pulse pressure amplification correlate with superoxide anion production but not with the severity of atherosclerosis in coronary arteries.

Biomarkers↗

PubMed2004

Dipyridamole inhibits hydroxylamine augmented nitric oxide (NO) production by activated polymorphonuclear neutrophils through an adenosine-independent mechanism.

Polymorphonuclear neutrophils (PMN) are thought to play a role in reperfusion injury and ischemia. These effects are partly mediated by toxic oxygen species (superoxide anion, hydrogen peroxide and hydroxyl radical) acting at the level of the endothelium. It was demonstrated recently that the superoxide anion reacts with nitric oxide (NO) and that interaction leads to the generation of highly toxic peroxynitrite. Several drugs were tested so far in order to affect PMN function. It was demonstrated that dipyridamole (2,6-bis-diethanolamino-4,8-dipiperidinopyrimido-(5,4-d)-pyrimidine) can influence neutrophil function by inhibiting adenosine uptake. However, this action can not fully explain all of the observed effects of dipyridamole action on PMN metabolism. The aim of our study was to evaluate the influence of dipyridamole on nitric oxide production by activated polymorphonuclear neutrophils. Incubation of PMNs with hydroxylamine (HA) and phorbol myristate acetate (PMA) generated nitrite (36.4+/-4.2 nmol/h 2x10(6) PMN), dipyridamole at 100 micromol/l, 50 micromol/l and 10 micromol/l caused a considerable drop in nitrite production (11.8+/-1.8, 19.7+/-2.7 and 27.4+/-3.2 nmol/h, respectively). Neither adenosine nor the adenosine analogue could mimic the dipyridamole effect. Moreover theophylline, an adenosine inhibitor could not reverse the dipirydamole action on PMN metabolism. We also found that dipyridamole inhibited hydrogen peroxide release from neutrophils. Catalase that scavenges hydrogen peroxide also largely abolished nitric oxide release from PMN. It is evident that dipyridamole inhibits hydroxylamine-augmented nitric oxide production by activated polymorphonuclear neutrophils through an adenosine-independent mechanism.

Adenosine↗

PubMed2003

Prospective evaluation of hydroperoxide plasma levels and stable nitric oxide end products in patients subjected to angioplasty for coronary artery disease.

BACKGROUND: Oxidative stress appears to be involved in several processes that contribute to atherogenesis and restenosis following vascular intervention. METHODS: The aim of our study was to evaluate prospectively the plasma concentrations of a hydroperoxide (ROOH) and nitric oxide end product (NO(x)) in patients subjected to coronary angioplasty (PTCA) and routine control angiography 6 months after the initial procedure. We prospectively studied 48 consecutive patients (39 men, nine women, mean age 52 years) with stable angina who underwent successful elective angioplasty. A vascular segment was considered successfully treated when the residual luminal narrowing in the dilated segment immediately after angioplasty was <50%. Angiographic follow-up was obtained in all of the patients. Plasma samples were drawn at baseline (before angioplasty) and serially after angioplasty (1, 3 and 6 months afterwards). Hydroperoxides were determined by the FOX II assay (ferrous oxidation in xylenol orange, Pierce Rockford, IL). Nitrate was converted in the presence of NO3 reductase. The Griess reagent was used for the measurement of NO2. RESULTS: The overall angiographic restenosis rate was 35%. There were no significant differences in clinical variables between the patients with or without restenosis. The baseline levels (0.8+/-0.09 vs. 0.6+/-0.2 micromol/l) as well as the concentrations of authentic lipid hydroperoxide in plasma after 1 month (0.7+/-0.09 vs. 1.0+/-0.2 micromol/l) and 6 months (0.8+/-0.1 vs. 1.0+/-0.2 micromol/l) were similar in both groups. Three months after the angioplasty a significant increase in the ROOH level was noticed in the patients with restenosis (0.9+/-0.1 vs. 1.4+/-0.2, P=0.04). Plasma levels of NO(x) were similar in both groups at baseline (23.6+/-2.1 vs. 22.7+/-2.6 micromol/l) and 1 month after procedure (24.4+/-2.2 vs. 23.4+/-3.3 micromol/l). However, in patients with restenosis significant decreases in stable NO end products were observed 3 and 6 months after PTCA (18.1+/-1.5 vs. 13.3+/-1.7, P=0.04; 14.2+/-1.0 vs. 8.7+/-1.3, P=0.02, respectively). CONCLUSIONS: In patients with angiographic restenosis a significant increase in lipid peroxidation accompanied by a reduction in the stable end products of nitric oxide in plasma is observed several months after PTCA.

Angioplasty, Balloon, Coronary↗

PubMed2000

The influence of treatment of hypercholesterolemic patients with simvastatin on plasma chemotactic activity and adherence of neutrophils.

BACKGROUND: there is some evidence to indicate that statins may affect the function of immune and inflammatory cells. This study investigates the influence of short term treatment with simvastatin on plasma chemotactic activity and adherence of polymorphonuclear neutrophils in hypercholesterolemic patients. METHODS AND RESULTS: 20 hypercholesterolemic patients (250-400 mg/dl) were given simvastatin (20 mg daily for 12 weeks). Peripheral blood samples were taken before and after 4 and 12 weeks of the therapy. The percentage of neutrophils adhering to plastic surface coated with albumin was significantly higher when cells were incubated with plasma obtained after 12 weeks of treatment with simvastatin in comparison with plasma collected before the therapy (unstimulated neutrophils: 5.945+/-0.475% vs. 8.155+/-0.96%, P=0.0477, stimulated neutrophils: 39.09+/-4.540% vs. 29.18+/-3.702%, P=0.032). There was a significant negative correlation between adherence of stimulated neutrophils and total cholesterol levels ((r)=-0.2796, 95% CI -0. 4999 to -0.02526, r(2)=0.07817, P=0.032). Migration of neutrophils towards plasma obtained after 12 weeks of treatment with simvastatin was significantly higher than towards plasma collected before the therapy (7.038+/-1.127 vs. 4.505+/-0 618 P=0.0475). CONCLUSION: treatment of hypercholesterolemic patients with simvastatin increases the chemotactic activity of plasma and augments the adherence of human neutrophils.

Anticholesteremic Agents↗

PubMed2000

Effects of trimetazidine on clinical symptoms and tolerance of exercise of patients with syndrome X: a preliminary study.

BACKGROUND: Trimetazidine diminishes angina and improves tolerance of exercise of patients with ischemic heart disease, and has no influence on blood pressure and heart rate. OBJECTIVE: To determine the effect of trimetazidine on angina symptoms and exercise tolerance in patients with syndrome X. METHODS: We investigated the effect of trimetazidine on the clinical symptoms and tolerance of exercise of 34 patients (20 women and 14 men, aged 32-60 years) with syndrome X (angina pectoris, positive result of exercise test, and normal coronary angiogram). The exercise test was performed before initiation of oral administration of trimetazidine therapy (20 mg three times a day) and 1 and 6 months thereafter. RESULTS: We obtained negative results of exercise treadmill tests for four patients (11.76%) after 1 month and five patients (14.71%) after 6 months of trimetazidine treatment. There was also a decrease in the incidence of effort angina after 6 months of treatment (26 patients or 76.47% before treatment versus 13 patients or 38.23% after 6 months of treatment). The drug had no significant influence on the heart rate and blood pressure. The duration for which patients could exercise was significantly prolonged by 1 month (652.9 +/- 206.2 versus 563.4 +/- 190.4 s, P = 0.0047) and 6 months (650.3 +/- 207.8 s, P = 0.0094) of treatment with trimetazidine. CONCLUSION: Treatment with trimetazidine decreases signs of angina during exercise and improves tolerance of exercise of patients with syndrome X.

Adult↗

PubMed1999

Fibrinolytic therapy and n-acetylocysteine in the treatment of patients with acute myocardial infarction: its influence on authentic plasma hydroperoxide levels and polymorphonuclear neutrophil oxygen metabolism.

Recently it has been demonstrated that the administration of n-acetylocysteine (NAC), in combination with streptokinase, significantly diminished oxidative stress in patients with myocardial infarction. The aim of our study was to assess the influence of NAC treatment, as adjunct therapy in an evolving myocardial infarction, on the polymorphonuclear count, superoxide anion and hydrogen peroxide levels and nitric oxide production by PMNs and authentic plasma hydroperoxide (ROOH). Treatment of patients with NAC in addition to reperfusion therapy was accompanied by a significant decrease in the number of circulating polymorphonuclear neutrophils. However, the oxygen metabolism of PMNs was not affected by NAC administration. The concentration of authentic plasma hydroperoxide was significantly reduced by the administration of NAC which suggests diminished oxidative stress during acute myocardial infarction.

Acetylcysteine↗

PubMed1998

Plasma chemotactic activity during dipyridamole induced myocardial ischemia.

BACKGROUND: We have previously reported that transient myocardial ischemia induced during exercise or dipyridamole challenge leads to the release of increased amounts of hydrogen peroxide into circulating blood. It would indicate that the temporary functional changes within myocardial cells may constitute there a sterile inflammatory area. Therefore we decided to evaluate the chemotactic properties of plasma in patients undergoing dipyridamole provocative test, as a sign of released inflammatory mediators. The ischemia occurrence was evaluated with 99mTc-SestaMIBI followed by single photon emission computed tomography (SPECT). METHODS: Blood samples were obtained from the peripheral vein of 42 patients (18 men and 24 women, mean age 61 years). Plasma chemotactic activity was determined by the use of the Boyden chamber method: immediately before dipyridamole challenge (time 0), 7, and 30 min after drug infusion. The migration of control polymorphonuclear neutrophils towards evaluated plasma samples was estimated. RESULTS: Chemotaxis of control PMNs towards plasma isolated from patients without signs of myocardial ischemia 7 min after dipyridamole administration was significantly diminished in comparison with baseline values (p=0.003). Plasma obtained 7 min after dipyridamole infusion from patients manifesting signs of myocardial ischemia by SPECT attracted control PMNs significantly more intensively in comparison to plasma isolated at time 0 (p=0.0005). CONCLUSIONS: The obtained results indicate that transient myocardial ischemia induced by dipyridamole challenge leads to generation of chemotactic factors detectable in peripheral blood plasma.

Angina Pectoris↗

PubMed1996

The influence of electrical cardioversion on superoxide anions (O2-) production by polymorphonuclear neutrophils, hydrogen peroxide (H2O2) plasma level and malondialdehyde serum concentration.

We studied the influence of electrical cardioversion on unstimulated and stimulated superoxide anion production by polymorphonuclear neutrophils in 22 patients with atrial flutter or atrial fibrillation. We also estimated hydrogen peroxide plasma level, as well as malondialdehyde serum concentration, in these subjects. We noted an increase in spontaneous production of superoxide anions from 14.9 +/- 1.8 nmol/10(6) neutrophils per 20 min to 21.37 +/- 2.7 nmol/10(6) neutrophils per 20 min (P = 0.002) in neutrophils obtained after electrical cardioversion. Similarly, stimulated production of O2- also increased after electrical cardioversion (41.8 +/ 3.4 nmol/10(6) neutrophils per 20 min vs. 59.0 +/- 5.9 nmol/10(6) neutrophils per 20 min, P = 0.0027). Moreover, hydrogen peroxide plasma level increased significantly after electrical cardioversion (39.9 +/- 6.2 mumol/l vs. 53.4 +/- 7.6 mol/l, P = 0.003). Serum malondialdehyde concentration also increased after countershock (2.56 +/- 0.26 nmol/ml vs. 2.94 +/- 0.26 nmol/ml, P = 0.023). These results seem to indicate that electrical cardioversion may lead to polymorphonuclear neutrophils activation, increased H2O2 production and lipid peroxidation.

Adult↗

PubMed1996

The influence of insulin-dependent diabetes mellitus (IDDM) duration on superoxide anion and hydrogen peroxide production by polymorphonuclear neutrophils.

We address the question whether oxygen metabolism of polymorphonuclear neutrophils (PMN) is influenced by disease duration in patients with insulin-dependent diabetes mellitus (IDDM). PMN were isolated from patients with IDDM of various durations and from healthy controls. We measured PMN production of superoxide anions (O2-) by cytochrome c reduction (see Babior, B.M. et al. (1973) J. Clin. Invest. 52, 741-746) and PMN production of hydrogen peroxide (H2O2) by phenol red oxygenation (see Pick, E. (1980) J. Immunol. Methods 38, 161-169) in three groups of IDDM patients subdivided according to disease duration (group A: IDDM less that 10 years; group B: IDDM of 10-15 years; group C: IDDM of more than 15 years) and in control healthy subjects (group H). Unstimulated O2- production in all IDDM patients was not statistically different from control values (A: 4.3 +/- 0.4 nmol/10(6) PMN per 30 min, nmol/10(6) PMN per 30 min; C: 4.9 +/- 0.9 nmol/10(6) PMN per 30 min; and H: 3.5 +/- 0.2 nmol/10(6) PMN per 30 min, respectively). In contrast, stimulated O2- production was significantly lower in both patients with 10-15 years, and patients with more than 15 years, duration of IDDM than in controls (B: 25.7 +/- 2.5 nmol/10(6) PMN per 30 min; C: 21.1 +/- 3.4 nmol/10(6) PMN per 30 min and H: 42.2 +/- 1.1 nmol/10(6) PMN per 30 min, respectively) correlating with disease duration (r = -0.44, P < 0.033). The stimulated O2- production in patients with less than 10 years duration of IDDM (A: 35.7 +/- 1.9 nmol/10(6) PMN per 30 min) was slightly lower than in controls. H2O2 production of unstimulated PMN (A: 4.0 +/- 0.5 nmol/10(6) PMN per 30 min; B: 4.4 +/- 0.8 nmol/10(6) PMN per 30 min and C: 4.4 +/-1.0 nmol/10(6) PMN per 30 min, respectively) was much higher than those in controls. In contrast, stimulated H2O2 production did not differ statistically from the value noticed in healthy subjects. The results obtained might indicate that production of H2O2 by unstimulated cells is increased in diabetic patients while generation of O2- by stimulated neutrophils is markedly impaired, suggesting that toxic oxygen species production might be influenced by disease duration.

Adult↗

PubMed1996

[Polymorphonuclear neutrophil adhesion in patients with diabetes mellitus].

The adherence of polymorphonuclear neutrophils was evaluated in patients with type I and type II diabetes as well as in group of elderly people. The adherence of these cells suspended in plasma: autologous, control, inactivated, zymosan-activated and in FMLP solution was estimated. The adherence of polymorphonuclear neutrophils obtained from controls after the suspension of cells in diabetic plasma was also estimated. The estimations were also performed after the heat-inactivation of diabetic plasma and its activation by zymosan. The obtained results seem to indicate that the enhanced adherence of polymorphonuclear neutrophils in diabetic patients is due to the presence of heterogeneous plasma factors.

Adolescent↗

PubMed1995

Metabolic control quality and free radical activity in diabetic patients.

The role of oxidative/reductive balance derangement in the pathogenesis of diabetic microangiopathy has often been discussed in the last few years. Therefore, we decided to evaluate the influence of intensive insulin therapy on selected indicators of free radical production. The levels of plasma hydrogen peroxide (H2O2) and serum malonyldialdehyde (MDA) were estimated in 15 patients with Type 1 and 15 with Type 2 diabetes before and after 2 weeks of intensive treatment. The initial H2O2 and MDA levels in all cases were significantly higher than in controls. After 2 weeks of treatment, the values for both estimated parameters were significantly lower; however, they were still higher than in the control group. Our results seem to confirm the previous suggestions concerning the relation between metabolic disturbances and oxidative stress in diabetic patients.

Adolescent↗

PubMed1995

Superoxide anion (O2-) production and bactericidal capacity of polymorphonuclear neutrophils obtained from patients subjected to glucagon test.

Superoxide anion (O2-) production and bactericidal capacity of morphologically mature bone marrow polymorphonuclear neutrophils (PMN) were evaluated in 30 haematologically normal individuals. These same parameters of peripheral PMNs were estimated in 15 healthy volunteers before and after glucagon-induced marrow granulocyte reserve mobilization. Bone marrow PMN in comparison with cells obtained from peripheral blood manifested impaired superoxide anion production and diminished bactericidal capacity. The admixture of bone marrow PMN released into the circulation by the use of glucagon administration significantly lowered both estimated PMN functions.

Adult↗

PubMed1995

Estimation of hydrogen peroxide plasma levels in patients evaluated for coronary heart disease using dipyridamole infusion followed by SPECT.

BACKGROUND: Prolonged ischemia leads to myocardial infarction and increased formation of toxic oxygen radicals. These substances exert deleterious effects on myocardial cells, contributing to reperfusion injury and generation of arrhythmia. Little information is available, however, concerning the toxic oxygen species generated during transient ischemia. The purpose of our study was to estimate hydrogen peroxide plasma levels in patients subjected to short-lasting ischemia induced by a dipyridamole stress test used for the diagnosis of coronary artery disease. Evaluation of the performed test was carried out with 99mTc-SestaMIBI followed by single photon emission computed tomography (SPECT). METHODS: Blood was obtained from peripheral veins of 53 patients (37 men and 16 women, mean age 49 +/- 11 years). Plasma hydrogen peroxide levels were estimated by spectrophotometric methods: immediately before a dipyridamole challenge and after drug infusion. RESULTS: Hydrogen peroxide plasma levels in patients with a negative SPECT test were 23.5 +/- 3.0 mumol/l (mean +/- SEM) and 21.0 +/- 2.9 after the dipyridamole infusion (P = 0.474). Plasma concentrations of hydrogen peroxide in patients with a positive SPECT test were 30.5 +/- 4.6 and increased after dipyridamole challenge to 50.3 +/- 5.4 (P = 0.004). Further analysis revealed that the observed difference cannot be attributed to previous history of myocardial infarction. CONCLUSIONS: Even transient myocardial ischemia can generate toxic oxygen derivatives. Evaluation of plasma levels of hydrogen peroxide may be of clinical relevance in patients with suspected coronary artery disease.

Coronary Disease↗

PubMed1995

Comparison of the influence of stress exercise test and transesophageal cardiac pacing on polymorphonuclear neutrophils functions.

Peripheral polymorphonuclear neutrophils (PMN) number, percent of PMN bearing IgG Fc receptors as well as PMN adherence were evaluated in 29 patients submitted to an exercise test. The peripheral PMN count significantly increased at the maximal work load. The increase in number of neutrophils bearing IgG Fc receptors was also noticed at that point, while PMN adherence to nylon wool columns did not change significantly. Nine subjects were additionally submitted to diagnostic transesophageal atrial pacing with a rate similar to maximal heart rate observed during the exercise test. It was revealed that atrial pacing in these patients had no influence on the peripheral PMN count, PMN adherence as well as number of neutrophils bearing IgG Fc receptors. We conclude, that granulocytosis observed during exercise can not be solely attributed to the increased heart rate and increased cardiac output but other mechanisms like muscle work play a significant role in this process.

Adult↗

PubMed1993

Effect of a monoclonal antibody to VLA-4 on lymphocyte adherence to microvascular and aortic endothelial cells.

Lymphocyte migration out of the blood to inflammatory sites is preceded by the adherence of lymphocytes to the vascular endothelium. This lymphocyte binding is enhanced by cytokine activation of the endothelial cells (EC). Small peritoneal exudate lymphocytes (sPEL) migrate preferentially into cutaneous inflammation and to skin injected with INF gamma, TNF alpha or LPS. These cells adhere also to rat microvascular EC and this adherence correlates well with migratory properties of sPEL. Lymphocyte EC adhesion is in part mediated by the VLA-4 molecule on the lymphocytes. Since differences between microvascular and large vessel EC have been described, we investigated whether sPEL adherence to both types of EC is governed by similar molecular mechanisms. Lymphocyte adhesion was low to unstimulated microvascular EC and augmented by pretreatment of EC with INF gamma, TNF alpha and LPS. In contrast, lymphocyte adhesion to unstimulated large vessel (aortic) EC was higher than to microvascular EC and could not be increased by cytokine or LPS treatment. Anti VLA-4 mAb inhibited the enhanced cytokine stimulated adhesion to microvascular EC without affecting adhesion of sPEL to unstimulated EC. Anti VLA-4 mAb inhibited the high spontaneous adhesion to aortic EC, suggesting that with both EC, adhesion is in part VLA-4 dependent.

Animals↗

PubMed1993

Impairment of the oxygen-dependent microbicidal mechanisms of polymorphonuclear neutrophils in patients with type 2 diabetes is not associated with increased susceptibility to infection.

Phagocytosis, bactericidal capacity and some selected parameters of oxygen-dependent bactericidal mechanisms were evaluated in 20 patients with type 2 diabetes being in similar (intermediate) state of metabolic control and in 15 healthy individuals. Polymorphonuclear neutrophils (PMNs) from diabetics showed normal ability to phagocytose staphylococci, a decreased Intracellular bacteria killing, the impaired stimulated superoxide anion (O2-) and hydrogen peroxide (H2O2) production and the low intracellular myeloperoxidase activity. The obtained data seem to indicate that the decreased bacterial killing by PMNs isolated from diabetics are partly at least related to an impairment of the oxygen-dependent bactericidal mechanisms. Since none of the diabetic patients suffered from recurrent infection the clinical significance of our finding is still uncertain.

Adult↗

PubMed1993

Peroxide plasma level in patients with coronary heart disease as a possible indicator of ischemia during exercise test.

BACKGROUND: This study evaluated the possible changes in production of free oxygen species during myocardial ischemia in the course of exercise testing of ischemic coronary disease. METHODS: Exercise testing was performed on 58 patients with suspected ischemic coronary disease. Plasma hydrogen peroxide (H2O2) level was assayed according to Frew et al. (Anal Chim Acta 1983, 155:139-150) in venous blood samples obtained before the test, at submaximal and maximal work loads, and after 30 minutes of rest. RESULTS: Hydrogen peroxide plasma level significantly increased (P < 0.001) at maximal work load in patients with positive exercise test results. Patients with negative exercise test results initially manifested a higher H2O2 level that dropped during maximal work load. CONCLUSIONS: The rise in plasma H2O2 level during myocardial ischemia indicates that intensification of oxygen free radical production occurs. This may be the result of hypoxanthine conversion by xanthine oxidase, catecholamine auto-oxidation, polymorphonuclear neutrophil activation, and/or derangement within mitochondrial electron transfer. The noticed difference between patients with a positive exercise test and those diagnosed as without ischemia may be of clinical relevance.

Adult↗

PubMed1993

Adherence of blood T cells to rat microvascular endothelial cells. Comparative studies of T lymphocytes isolated from various tissues.

Lymphocytes isolated from various tissues exhibit different magnitudes of adherence to endothelial cells (EC) in vitro. Nevertheless, a good correlation between the lymphocyte adherence to EC in vitro and their migratory properties to sites of inflammation in vivo was found. The main goal of this study was to compare, using unstimulated and IFN-gamma-, TNF-alpha- or LPS-pretreated EC, the adherence of T cells isolated from blood (BTC), with the adherence of T lymphocytes obtained from other tissues. The results show that BTC belong to poorly adhering cells. However, their adherence was increased about 3-fold, when EC were pretreated with IFN-gamma, TNF-alpha or LPS. This adherence was very similar to that observed for lymph node T cells (LNTC) and 2-3 times lower than the adherence of spleen T cells (SpTC) and peritoneal exudate T cells (PETC). In some experiments, T lymphocytes were incubated for 1 h with concanavalin A (Con A) and this led to the highest increase of BTC adherence, but the enhancement of the adherence was significantly smaller than the increase noted for SpTC and PETC. The differences in the adherence of lymphocytes isolated from various tissues may suggest that different adhesion molecules are responsible for their binding to EC.

Animals↗