Increased Endothelial Cell-Leukocyte Interaction in Murine Schistosomiasis: Possible Priming of Endothelial Cells by the Disease

Background and Aims: Schistosomiasis is an intravascular parasitic disease associated with inflammation. Endothelial cells control leukocyte transmigration and vascular permeability being modulated by pro-inflammatory mediators. Recent data have shown that endothelial cells primed in vivo in the course of a disease keep the information in culture. Herein, we evaluated the impact of schistosomiasis on endothelial cell-regulated events in vivo and in vitro. Methodology and Principal Findings: The experimental groups consisted of Schistosoma mansoni-infected and age-matched control mice. In vivo infection caused a marked influx of leukocytes and an increased protein leakage in the peritoneal cavity, characterizing an inflamed vascular and cellular profile. In vitro leukocyte-mesenteric endothelial cell adhesion was higher in cultured cells from infected mice as compared to controls, either in the basal condition or after treatment with the pro-inflammatory cytokine tumor necrosis factor (TNF). Nitric oxide (NO) donation reduced leukocyte adhesion to endothelial cells from control and infected groups; however, in the later group the effect was more pronounced, probably due to a reduced NO production. Inhibition of control endothelial NO synthase (eNOS) increased leukocyte adhesion to a level similar to the one observed in the infected group. Besides, the adhesion of control leukocytes to endothelial cells from infected animals is similar to the result of infected animals, confirming that schistosomiasis alters endothelial cells function. Furthermore, NO production as well as the expression of eNOS were reduced in cultured endothelial cells from infected animals. On the other hand, the expression of its repressor protein, namely caveolin-1, was similar in both control and infected groups. Conclusion/Significance: Schistosomiasis increases vascular permeability and endothelial cell-leukocyte interaction in vivo and in vitro. These effects are partially explained by a reduced eNOS expression. In addition, our data show that the disease primes endothelial cells in vivo, which keep the acquired phenotype in culture.

Five-year follow-up of angiographic disease progression after medicine, angioplasty, or surgery

Background: Progression of atherosclerosis in coronary artery disease is observed through consecutive angiograms. Prognosis of this progression in patients randomized to different treatments has not been established. This study compared progression of coronary artery disease in native coronary arteries in patients undergoing surgery, angioplasty, or medical treatment. Methods: Patients (611) with stable multivessel coronary artery disease and preserved ventricular function were randomly assigned to CABG, PCI, or medical treatment alone (MT). After 5-year follow-up, 392 patients (64%) underwent new angiography. Progression was considered a new stenosis of >= 50% in an arterial segment previously considered normal or an increased grade of previous stenosis > 20% in nontreated vessels. Results: Of the 392 patients, 136 underwent CABG, 146 PCI, and 110 MT. Baseline characteristics were similar among treatment groups, except for more smokers and statin users in the MT group, more hypertensives and lower LDL-cholesterol levels in the CABG group, and more angina in the PCI group at study entry. Analysis showed greater progression in at least one native vessel in PCI patients (84%) compared with CABG (57%) and MT (74%) patients (p < 0.001). LAD coronary territory had higher progression compared with LCX and RCA (P < 0.001). PCI treatment, hypertension, male sex, and previous MI were independent risk factors for progression. No statistical difference existed between coronary events and the development of progression. Conclusion: The angioplasty treatment conferred greater progression in native coronary arteries, especially in the left anterior descending territories and treated vessels. The progression was independently associated with hypertension, male sex, and previous myocardial infarction.

The Lectin ArtinM Induces Recruitment of Rat Mast Cells from the Bone Marrow to the Peritoneal Cavity

Background: The D-mannose binding lectin ArtinM is known to recruit neutrophils, to degranulate mast cells and may have potential therapeutic applications. However, the effect of ArtinM on mast cell recruitment has not been investigated. Methodology: Male Wistar rats were injected i.p. with ArtinM or ConA (control). The ability of the lectin to degranulate peritoneal and mesenteric mast cells was examined. Recruitment of mast cells to the peritoneal cavity and mesentery after ArtinM injection was examined with or without depletion of peritoneal mast cells by distilled water. Results: ArtinM degranulated both peritoneal and mesentery mast cells in vitro. Three days after i.p. injection of the lectin there were reduced numbers of mast cells in the peritoneal lavage, while at 7 days post injection of ArtinM, the number of peritoneal mast cells was close to control values. Since immature mast cells are recruited from the bone marrow, the effect of the lectin on bone marrow mast cells was examined. Injection of ArtinM resulted in an increased number of mast cells in the bone marrow. To determine if degranulation of mast cells in the peritoneal cavity was required for the increase in bone marrow mast cells, the peritoneal cavity was depleted of mast cells with ultrapure water. Exposure to ArtinM increased the number of mast cells in the bone marrow of rats depleted of peritoneal mast cells. Conclusions: The ArtinM induced recruitment of mast cells from the bone marrow to the peritoneal cavity may partially explain the therapeutic actions of ArtinM.

Effect of the effluent released from the canine internal mammary artery after intraluminal and extraluminal perfusion of acetylcholine and adenosine diphosphate

Segments of the canine internal mammary artery (35 mm in length) were suspended in vitro in an organ chamber containing physiological salt solution (95% O(2)/5% CO(2), pH = 7.4, 37 degrees C). Segments were individually cannulated and perfused at 5 ml/minute using a roller pump. Vasorelaxant activity of the effluent from the perfused internal mammary arteries was bioassayed by measuring the decrease in tension induced by the effluent of the coronary artery endothelium-free ring which had been contracted with prostaglandin F(2 alpha) (2 x 10(-6) M). Intraluminal perfusion of adenosine diphosphate (10(-5) M) induced significant increase in relaxant activity in the effluent from the perfused blood vessel. However, when adenosine diphosphate (10(-5) M) was added extraluminally to the internal mammary artery, no change in relaxant activity in the effluent was noted. In contrast, acetylcholine produced significant increase in the relaxant activity on the effluent of the perfused internal mammary artery with both intraluminal and extraluminal perfusion. The intraluminal and extraluminal release of endothelium-derived relaxing factor (EDRF) by acetylcholine (10(-5) M) can be inhibited by site-specific administration of atropine (10(-5) M). These experiments indicate that certain agonists can induce the release of EDRF only by binding to intravascular receptors while other agonists can induce endothelium-dependent vasodilatation by acting on neural side receptors.

Videodensitometric analysis of advanced carotid plaque: correlation with MMP-9 and TIMP-1 expression

Background: Matrix metalloproteinase-9 (MMP-9) and tissue inhibitor of MMP (TIMP) promote derangement of the extracellular matrix, which is ultimately reflected in plaque images seen on ultrasound. Videodensitometry can identify structural disturbances in plaques. Objectives: To establish the correlations between values determined using videodensitometry in B-mode ultrasound images of advanced carotid plaques and the total expression of MMP-9 and TIMP-1 in these removed plaques. Methods: Thirty patients underwent ultrasonic tissue characterization of carotid plaques before surgery, using mean gray level (MGL), energy, entropy and homogeneity. Each patient was assigned preoperatively to one of 2 groups: group I, symptomatic patients (n = 16; 12 males; mean age 66.7 +/- 6.8 years), and group II, asymptomatic patients (n = 14; 8 males; mean age 67.6 +/- 6.81 years). Tissue specimens were analyzed for MMP-9 and TIMP-1 expression. Nine carotid arteries were used as normal tissue controls. Results: MMP-9 expression levels were elevated in group II and in normal tissues compared to group I (p < 0.001). TIMP-1 levels were higher in group II than in group I, and significantly higher in normal tissues than in group I (p = 0.039). The MGL was higher in group II compared to group I (p = 0.038). Energy had greater values in group II compared to group I (p = 0.02). There were no differences between patient groups in homogeneity and entropy. Energy positively correlated with MMP-9 and TIMP-1 expression (p = 0.012 and p = 0.031 respectively). Homogeneity positively correlated with MMP-9 and TIMP-1 expression (p = 0.034 and p = 0.047 respectively). There were no correlations between protein expression and MGL or entropy. Conclusions: Videodensitometric computer analysis of ultrasound scanning images can be used to identify stable carotid plaques, which have higher total expression levels of MMP-9 and TIMP-1 than unstable plaques.

Placentation in Sigmodontinae: a rodent taxon native to South America

Background: Sigmodontinae, known as ""New World rats and mice,"" is a large subfamily of Cricetidae for which we herein provide the first comprehensive investigation of the placenta. Methods: Placentas of various gestational ages ranging from early pregnancy to near term were obtained for five genera, i.e. Necromys, Euryoryzomys, Cerradomys, Hylaeamys, and Oligoryzomys. They were investigated by means of histology, immunohistochemistry, a proliferation marker, DBA-lectin staining and transmission electron microscopy. Results: The chorioallantoic placenta was organized in a labyrinthine zone, spongy zone and decidua and an inverted yolk sac persisted until term. The chorioallantoic placenta was hemotrichorial. The interhemal barrier comprised fetal capillary endothelium and three layers of trophoblast, an outermost, cellular layer and two syncytial ones, with interspersed trophoblast giant cells (TGC). In addition, accumulations of TGC occurred below Reichert's membrane. The junctional zone contained syncytial trophoblast, proliferative cellular trophoblast, glycogen cells and TGC that were situated near to the maternal blood channels. In three of the genera, TGC were also accumulated in distinct areas at the placental periphery. PAS-positive glycogen cells derived from the junctional zone invaded the decidua. Abundant maternal uNK cells with positive response to PAS, vimentin and DBA-lectin were found in the decidua. The visceral yolk sac was completely inverted and villous. Conclusion: The general aspect of the fetal membranes in Sigmodontinae resembled that found in other cricetid rodents. Compared to murid rodents there were larger numbers of giant cells and in some genera these were seen to congregate at the periphery of the placental disk. Glycogen cells were found to invade the decidua but we did not identify trophoblast in the walls of the deeper decidual arteries. In contrast these vessels were surrounded by large numbers of uNK cells. This survey of wild-trapped specimens from five genera is a useful starting point for the study of placentation in an important subfamily of South American rodents. We note, however, that some of these rodents can be captive bred and recommend that future studies focus on the study of time dated pregnancies.

The case of thyroid hormones: how to learn physiology by solving a detective case

Lellis-Santos C, Giannocco G, Nunes MT. The case of thyroid hormones: how to learn physiology by solving a detective case. Adv Physiol Educ 35: 219-226, 2011; doi:10.1152/advan.00135.2010.Thyroid diseases are prevalent among endocrine disorders, and careful evaluation of patients' symptoms is a very important part in their diagnosis. Developing new pedagogical strategies, such as problem-based learning (PBL), is extremely important to stimulate and encourage medical and biomedical students to learn thyroid physiology and identify the signs and symptoms of thyroid dysfunction. The present study aimed to create a new pedagogical approach to build deep knowledge about hypo-/hyperthyroidism by proposing a hands-on activity based on a detective case, using alternative materials in place of laboratory animals. After receiving a description of a criminal story involving changes in thyroid hormone economy, students collected data from clues, such as body weight, mesenteric vascularization, visceral fat, heart and thyroid size, heart rate, and thyroid-stimulating hormone serum concentration to solve the case. Nevertheless, there was one missing clue for each panel of data. Four different materials were proposed to perform the same practical lesson. Animals, pictures, small stuffed toy rats, and illustrations were all effective to promote learning, and the detective case context was considered by students as inviting and stimulating. The activity can be easily performed independently of the institution's purchasing power. The practical lesson stimulated the scientific method of data collection and organization, discussion, and review of thyroid hormone actions to solve the case. Hence, this activity provides a new strategy and alternative materials to teach without animal euthanization.

Low nanomolar concentration of mercury chloride increases vascular reactivity to phenylephrine and local angiotensin production in rats

Exposure to mercury at nanomolar level affects cardiac function but its effects on vascular reactivity have yet to be investigated. Pressor responses to phenylephrine (PHE) were investigated in perfused rat tail arteries before and after treatment with 6 nM HgCl2 during 1 h,,in the presence (E+) and absence (E-) of endothelium, after L-NAME (10(-4) M), indomethacin (10(-5) M), enalaprilate (1 mu M), tempol (1 mu M) and deferoxamine (300 mu M) treatments. HgCl2 increased sensitivity (pD(2)) without modifying the maximum response (Em) to PHE, but the pD(2) increase was abolished after endothelial damage. L-NAME treatment increased pD(2) and Emax. However, in the presence of HgCl2, this increase was smaller, and it did not modify Emax. After indomethacin treatment, the increase of pD(2) induced by HgCl2 was maintained. Enalaprilate, tempol and deferoxamine reversed the increase of pD(2) evoked by HgCl2. HgCl2 increased the angiotensin converting enzyme (ACE) activity explaining the result obtained with enalaprilate. Results suggest that at nanomolar concentrations HgCl2 increase the vascular reactivity to PHE. This response is endothelium mediated and involves the reduction of NO bioavailability and the action of reactive oxygen species. The local ACE participates in mercury actions and depends on the angiotensin 11 generation. (c) 2007 Elsevier Inc. All rights reserved.

A transient three-dimensional heat transfer model of the human body

The objective of this work is to develop an improved model of the human thermal system. The features included are important to solve real problems: 3D heat conduction, the use of elliptical cylinders to adequately approximate body geometry, the careful representation of tissues and important organs, and the flexibility of the computational implementation. Focus is on the passive system, which is composed by 15 cylindrical elements and it includes heat transfer between large arteries and veins. The results of thermal neutrality and transient simulations are in excellent agreement with experimental data, indicating that the model represents adequately the behavior of the human thermal system. (C) 2009 Elsevier Ltd. All rights reserved.

Cardiovascular Simulator Improvement: Pressure Versus Volume Loop Assessment

This article presents improvement on a physical cardiovascular simulator (PCS) system. Intraventricular pressure versus intraventricular volume (PxV) loop was obtained to evaluate performance of a pulsatile chamber mimicking the human left ventricle. PxV loop shows heart contractility and is normally used to evaluate heart performance. In many heart diseases, the stroke volume decreases because of low heart contractility. This pathological situation must be simulated by the PCS in order to evaluate the assistance provided by a ventricular assist device (VAD). The PCS system is automatically controlled by a computer and is an auxiliary tool for VAD control strategies development. This PCS system is according to a Windkessel model where lumped parameters are used for cardiovascular system analysis. Peripheral resistance, arteries compliance, and fluid inertance are simulated. The simulator has an actuator with a roller screw and brushless direct current motor, and the stroke volume is regulated by the actuator displacement. Internal pressure and volume measurements are monitored to obtain the PxV loop. Left chamber internal pressure is directly obtained by pressure transducer; however, internal volume has been obtained indirectly by using a linear variable differential transformer, which senses the diaphragm displacement. Correlations between the internal volume and diaphragm position are made. LabVIEW integrates these signals and shows the pressure versus internal volume loop. The results that have been obtained from the PCS system show PxV loops at different ventricle elastances, making possible the simulation of pathological situations. A preliminary test with a pulsatile VAD attached to PCS system was made.

Normal Doppler velocimetry of renal vasculature in Persian cats

Renal diseases are common in older cats. Decreased renal blood flow may be the first sign of dysfunction and can be evaluated by Doppler ultrasound. But previous studies suggest that the resistive index (RI) has a low sensitivity for detecting renal disease. Doppler waveforms of renal and intrarenal arteries demonstrate decreased blood flow before there are any changes in the RI. The purpose of this study was to evaluate the normal Doppler flowmetrics parameters of renal arteries (RAs), interlobar arteries (IAs) and abdominal aorta (AO) in adult healthy, Persian cats. Twenty-five Persian cats (13 females and 12 males with mean age of 30 months and an age range 12-60 months) with normal clinical examinations and biochemical tests and normal systemic blood pressure were given B-mode ultrasonographies in order to exclude all nephropathies, including polycystic kidney disease. All measurements were performed on both kidneys. Both kidneys (n = 50) were examined by color mapping of the renal vasculature. Pulsed Doppler was used to examine both RAs, the IAs at cranial, middle and caudal sites, and the AO. The RI was calculated for all of the vessels. Early systolic acceleration (ESA) of RA and IA was obtained with Doppler spectral analysis. Furthermore, the ratio indices between RA/AO, and IA/RA velocities were calculated. The mean values of peak systolic velocity (PSV) and the diameter for AO were 53.17 +/- 13.46 cm/s and 0.38 +/- 0.08 cm, respectively. The mean RA diameter for all 50 kidneys was 0.15 +/- 0.02 cm. Considering the velocimetric values in both RAs, the mean PSV and RI that were obtained were 41.17 +/- 9.40 cm/s and 0.54 +/- 0.07. The RA had a mean ESA of 1.12 +/- 1.14 m/s(2) and the calculated upper limit of the reference value was 3.40 m/s(2). The mean renal-aortic ratio was 0.828 +/- 0.296. The IA showed PSV and RI values of 32.16 +/- 9.33 cm/s and 0.52 +/- 0.06, respectively. The mean ESA of all IAs was 0.73 +/- 0.61 m/s(2). The calculated upper limit of the reference value was 2.0 m/s(2). The mean renal-interlobar artery ratio was 1.45 +/- 0.57. The RI values obtained in this study were similar to values reported in the literature. Some conditions that lead to a decrease in compliance and to an increase in vascular resistance can affect the Doppler spectral waveforms without changes in RI. To our knowledge, there are no studies that were directed toward to the normal ESA values of the renal vasculature in Persian cats. This study introduced a new ratio between the PSV of the RA and the IA. This index was developed based on the well-known effects of Doppler on the detection of stenosis, regardless of the cause. Further studies are necessary to verify the hemodynamic behavior of this index under pathological conditions in cats as well as the effect of aging, nephropathies and systemic pressure on Doppler velocimetric parameters. (C) 2010 ISFM and AAFP. Published by Elsevier Ltd. All rights reserved.

Blood pressure variability increases connexin expression in the vascular smooth muscle of rats

Aims Following sinoaortic denervation (SAD), isolated rat aortas present oscillatory contractions and demonstrate a heightened contraction for alpha-adrenergic agonists. Our aim was to verify the effects of SAD on connexin43 (Cx43) expression and phenylephrine-induced contraction in isolated aortas. Methods and results Three days after surgery (SAD or sham operation), isolated aortic rings were exposed to phenylephrine and acetylcholine (0.1-10 mu M) in the presence or absence of the gap junction blocker 18 beta-glycyrrhetinic acid (18 beta-GA, 100 mu M). Vascular reactivity to potassium chloride (KCl, 4.7-120 mM) was also examined. The incidence of rats presenting oscillatory contractions was measured. Effects of SAD on the vascular smooth muscle expression of the Cx43 mRNA by RT-PCR and western blotting for Cx43 protein were examined. Phenylephrine-induced contraction was higher in SAD rat aortas compared with the control. In the presence of 18 beta-GA, the response to phenylephrine was similar in both groups. Oscillatory contractions were observed in 10/10 SAD rat aortas vs. 2/10 controls. Relaxing response to acetylcholine was similar in both groups, but in the presence of 18 beta-GA, the response to acetylcholine decreased significantly in the sham-operated group (82.7 +/- 7.6% reduction of relaxation), whereas a half-maximal relaxation (reduction of 46.2 +/- 5.3%) took place in SAD rat aortas. KCl-induced contraction was similar in both groups. Following SAD, RT-PCR revealed significantly increased levels of Cx43 mRNA (9.85 fold, P < 0.01). Western blot analysis revealed greater levels of Cx43 protein (P < 0.05). Conclusion Blood pressure variability evoked by SAD leads to increased expression of Cx43, which could contribute to enhanced phenylephrine-induced contraction and oscillatory activity in isolated aortas.

Chronic ethanol intake modulates vascular levels of endothelin-1 receptor and enhances the pressor response to endothelin-1 in anaesthetized rats

Background and purpose: The contribution of endothelin-1 (ET-1) to vascular hyper-reactivity associated with chronic ethanol intake, a major risk factor in several cardiovascular diseases, remains to be investigated. Experimental approach: The biphasic haemodynamic responses to ET-1 (0.01-0.1 nmol kg(-1), i.v.) or to the selective ET(B) agonist, IRL1620 (0.001-1.0 nmol kg(-1), i.v.), with or without ET(A) or ET(B) antagonists (BQ123 (c(DTrp-Dasp-Pro-Dval-Leu)) at 1 and 2.5 mg kg(-1) and BQ788 (N-cis-2,6-dimethyl-piperidinocarbonyl-L-gamma-methylleucyl1-D-1methoxycarbonyltryptophanyl-D-norleucine) at 0.25 mg kg(-1), respectively) were tested in anaesthetized rats, after 2 weeks` chronic ethanol treatment. Hepatic parameters and ET receptor protein levels were also determined. Key results: The initial hypotensive responses to ET-1 or IRL1620 were unaffected by chronic ethanol intake, whereas the subsequent pressor effects induced by ET-1, but not by IRL1620, were potentiated. BQ123 at 2.5 but not 1 mg kg(-1) reduced the pressor responses to ET-1 in ethanol-treated rats. Conversely, BQ788 (0.25 mg kg(-1)) potentiated ET-1-induced increases in mean arterial blood pressure in control as well as in ethanol-treated rats. Interestingly, in the latter group, increases in heart rate, induced by ET-1 at a dose of 0.025 mg kg(-1) were enhanced following ET(B) receptor blockade. Finally, we observed higher levels of ET(A) receptor in the heart and mesenteric artery and a reduction of ET(B) receptor protein levels in the aorta and kidney from rats chronically treated with ethanol. Conclusions and implications: Increased vascular reactivity to ET-1 and altered protein levels of ET(A) and ET(B) receptors could play a role in the pathogenesis of cardiovascular complications associated with chronic ethanol consumption.

Balloon catheter injury abolishes phenylephrine-induced relaxation in the rat contralateral carotid

BACKGROUND AND PURPOSE The consequences of compensatory responses to balloon catheter injury in rat carotid artery, on phenylephrine-induced relaxation and contraction in the contralateral carotid artery were studied. EXPERIMENTAL APPROACH Relaxation and contraction concentration-response curves for phenylephrine were obtained for contralateral carotid arteries in the presence of indomethacin (COX inhibitor), SC560 (COX-1 inhibitor), SC236 (COX-2 inhibitor) or 4-hydroxytetramethyl-L-piperidine-1-oxyl (tempol; superoxide dismutase mimetic). Reactive oxygen species were measured in carotid artery endothelial cells fluorimetrically with dihydroethidium. KEY RESULTS Phenylephrine-induced relaxation was abolished in contralateral carotid arteries from operated rats (E(max) = 0.01 +/- 0.004 g) in relation to control (E(max) = 0.18 +/- 0.005 g). Phenylephrine-induced contractions were increased in contralateral arteries (E(max) = 0.54 +/- 0.009 g) in relation to control (E(max) = 0.38 +/- 0.014 g). SC236 restored phenylephrine-induced relaxation (E(max) = 0.17 +/- 0.004 g) and contraction (E(max) = 0.34 +/- 0.018 g) in contralateral arteries. Tempol restored phenylephrine-induced relaxation (E(max) = 0.19 +/- 0.012 g) and contraction (E(max) = 0.42 +/- 0.014 g) in contralateral arteries, while apocynin did not alter either relaxation (E(max) = 0.01 +/- 0.004 g) or contraction (E(max) = 0.54 +/- 0.009 g). Dihydroethidium fluorescence was increased in contralateral samples (18 882 +/- 435 U) in relation to control (10 455 +/- 303 U). SC236 reduced the fluorescence in contralateral samples (8250 +/- 365 U). CONCLUSIONS AND IMPLICATIONS Balloon catheter injury abolished phenylephrine-induced relaxation and increased phenylephrine-induced contraction in contralateral carotid arteries, through O(2)(-) derived from COX-2.

Impaired calcium influx despite hyper-reactivity in contralateral carotid following balloon injury: eNOS involvement

Balloon catheter injury results in hyper-reactivity to phenylephrine in contralateral carotids. Decreased nitric oxide (NO) modulation and/or increased intracellular calcium concentration triggers vascular smooth muscle contraction. Therefore, this study explores the participation of NO signaling pathway and calcium mobilization on hyper-reactivity to phenylephrine in contralateral carotids. Concentration-response curves for calcium (CaCl(2)) and phenylephrine were obtained in control and contralateral carotids four days after balloon injury, in the presence and absence of the inhibitors (L-NAME, L-NNA, 1400W, 7-NI, Oxyhemoglobin, ODQ or Tiron). Confocal microscopy using Fluo-3AM or DHE was performed to detect the intracellular levels of calcium and reactive oxygen species, respectively. The modulation of NO on phenylephrine-induced contraction was absent in the contralateral carotid. Phenylephrine-induced intracellular calcium mobilization was not altered in contralateral carotids. However, extracellular calcium mobilization by phenylephrine was reduced in the contralateral carotid compared to control arteries, and this result was confirmed by confocal microscopy. L-NAME increased phenylephrine-induced extracellular calcium mobilization in the contralateral carotid to the control levels. Results obtained with L-NNA, 1400W, 7-NI, OxyHb, ODQ or Tiron showed that this response was mediated by products from endothelial NOS (eNOS) different from NO and without soluble guanylate cyclase activation, but it involved superoxide anions. Furthermore. Tiron or L-NNA reduced the levels of reactive oxygen species in contralateral carotids. Data suggest that balloon catheter injury promoted eNOS uncoupling in contralateral carotids, which generates superoxide rather than NO, and reduces phenylephrine-induced extracellular calcium mobilization, despite the hyper-reactivity to phenylephrine in contralateral carotids. (C) 2010 Elsevier B.V. All rights reserved.